Subject: RE: GraGraph home earthquake meter From: "Kareem of Heyjoojoo" system98765@............. Date: Sun, 30 Sep 2007 13:13:00 -0700 I thought it was $85 but that link shows $159... (american dollars) -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of JimT Sent: Sunday, September 30, 2007 8:40 AM To: psn-l@.............. Subject: Re: GraGraph home earthquake meter There is more info on this page: http://www.kilian-nakamura.com/catalog/gragraph-home-earthquake-seismograph- p-176.html Here is what it says: The Gragraph is a home seismograph that warns you as an earthquake is occurring, measures the intensity, and records the data in its calendar. The verbal warnings are in Japanese, but the digital data can be easily accessed in any language. In normal mode, the Gragraph serves as a tabletop calendar/clock and a reference for past activity. Gragraph features: .. Perceives shaking, and indicates on display . Warns of shaking with sound and voice . Indicates level from 3-10 . Keeps record of previous seismic activity . During the night, it activates a safety light . Calendar/Clock function Jim Turner On 9/29/07, psn-l-digest-request@.............. wrote: > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: GraGraph home earthquake meter > From: "David Saum" > Date: Sat, 29 Sep 2007 18:40:00 -0400 > > Japanese > http://www.gragraph.jp/ > > English > http://blog.scifi.com/tech/archives/2007/09/28/gragraph_home_e.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? From: Dave Nelson davenn@............... Date: Mon, 01 Oct 2007 09:47:23 +1000 Hi Stephen, yeah damn annoying, some weeks ago I emailed Madelene Zirbies who is one of the ones looking after the www site. She was aware of it and seemed to indicate that it wasnt going to get fixed any time soon. the other data available under the Scientific & Technical tab just isnt the same :( for one it doesnt have the nice world map image with the "beachball" on it that I had saved on puter for many years. also the data is in a different format. also the "Global CMT Project Moment Tensor Solution" info now being supplied lists events Mw6.0 and higher and some times only the high events eg M6.6 up cheers Dave N Sydney At 11:27 AM 9/30/2007 -0700, you wrote: >Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007? >I know that I can get the info in a few days under the Scientific & >Technical tab of the individual quakes at NEIC, but was wondering what >happened to their FM Tensor list at the following link??? >http://neic.usgs.gov/neis/FM/ > Stephen > PSN #55 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.35/1039 - Release Date: 9/29/2007 9:46 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? From: John Lahr johnjan@........ Date: Mon, 01 Oct 2007 14:29:38 -0700 Here's the word from the USGS. Cheers, John Because of Department of Interior security requirements, we had to install a number of new routers in our internal network. At that point some of our processes that depended on communication between different subnets stopped working. In other words, some of our programs broke. Most of the problems were fixed on the first day, but we are still unable to compute the moment tensors. We have been working on a new, faster experimental system, with an improved user interface, for generating the moment tensors. Since this is the direction we were already committed to, we have decided to accelerate implementation of the new system. In the near future we hope to be computing moment tensors again, using the new system. You may want to take a look at the USGS Earthquake Notification Service (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These notifications, at this time, will not include the "beachball", but will be A LOT faster. They are also very easy to customize in terms of geographic region(s) of interest and magnitude threshold. You may end up preferring these to the moment tensor solutions. At 04:47 PM 9/30/2007, you wrote: >Hi Stephen, > yeah damn annoying, some weeks ago I emailed > Madelene Zirbies > who is one of the ones looking after the www site. She was aware of it and >seemed to indicate that it wasnt going to get fixed any time soon. > > the other data available under the Scientific & Technical tab just >isnt the same :( for one it doesnt have the nice world map image with the >"beachball" on it that I had saved on puter for many years. also >the data is in >a different format. also the "Global CMT Project Moment Tensor >Solution" info >now being supplied lists events Mw6.0 and higher and some times >only the high >events eg M6.6 up > >cheers >Dave N >Sydney > > > >At 11:27 AM 9/30/2007 -0700, you wrote: >>Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007? >>I know that I can get the info in a few days under the Scientific & >>Technical tab of the individual quakes at NEIC, but was wondering >>what happened to their FM Tensor list at the following link??? >>http://neic.usgs.gov/neis/FM/ >> Stephen >> PSN #55 > > >-- >No virus found in this outgoing message. >Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: >269.13.35/1039 - Release Date: 9/29/2007 9:46 PM > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with the body >of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? From: Dave Nelson davenn@............... Date: Tue, 02 Oct 2007 07:53:09 +1000 Thanks John nice to have an official explanation, hopefully we will see the "beachball maps again one day soon. Yes I have been logged onto the ENS for some years and it is a good fast notification of new events. cheers Dave At 02:29 PM 10/1/2007 -0700, you wrote: >Here's the word from the USGS. Cheers, John > Because of Department of Interior security requirements, we had to > install a number of new routers in our internal network. At that point > some of our processes that depended on communication between different > subnets stopped working. In other words, some of our programs broke. > Most of the problems were fixed on the first day, but we are still > unable to compute the moment tensors. > We have been working on a new, faster experimental system, with an > improved user interface, for generating the moment tensors. Since this > is the direction we were already committed to, we have decided to > accelerate implementation of the new system. In the near future we hope > to be computing moment tensors again, using the new system. > You may want to take a look at the USGS Earthquake Notification Service > (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These notifications, > at this time, will not include the "beachball", but will be A LOT > faster. They are also very easy to customize in terms of geographic > region(s) of interest and magnitude threshold. You may end up preferring > these to the moment tensor solutions. > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.35/1040 - Release Date: 9/30/2007 9:01 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? Working!!! From: Stephen & Kathy skmort@............ Date: Mon, 01 Oct 2007 18:57:49 -0700 Wouldn't you know,, we must have jarred something loose,, ha,, I just checked and today it is working,,, thanks to all. Stephen PSN #55 John Lahr wrote: > Here's the word from the USGS. Cheers, John > > Because of Department of Interior security requirements, we had to > install a number of new routers in our internal network. At that point > some of our processes that depended on communication between different > subnets stopped working. In other words, some of our programs broke. > Most of the problems were fixed on the first day, but we are still > unable to compute the moment tensors. > > > We have been working on a new, faster experimental system, with an > improved user interface, for generating the moment tensors. Since this > is the direction we were already committed to, we have decided to > accelerate implementation of the new system. In the near future we > hope > to be computing moment tensors again, using the new system. > > > You may want to take a look at the USGS Earthquake Notification > Service > (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These > notifications, > at this time, will not include the "beachball", but will be A LOT > faster. They are also very easy to customize in terms of geographic > region(s) of interest and magnitude threshold. You may end up > preferring > these to the moment tensor solutions. > > > > > > > At 04:47 PM 9/30/2007, you wrote: >> Hi Stephen, >> yeah damn annoying, some weeks ago I emailed >> Madelene Zirbies >> who is one of the ones looking after the www site. She was aware >> of it and >> seemed to indicate that it wasnt going to get fixed any time soon. >> >> the other data available under the Scientific & Technical tab just >> isnt the same :( for one it doesnt have the nice world map image >> with the >> "beachball" on it that I had saved on puter for many years. also >> the data is in >> a different format. also the "Global CMT Project Moment Tensor >> Solution" info >> now being supplied lists events Mw6.0 and higher and some times >> only the high >> events eg M6.6 up >> >> cheers >> Dave N >> Sydney >> >> >> >> At 11:27 AM 9/30/2007 -0700, you wrote: >>> Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007? >>> I know that I can get the info in a few days under the Scientific & >>> Technical tab of the individual quakes at NEIC, but was wondering >>> what happened to their FM Tensor list at the following link??? >>> http://neic.usgs.gov/neis/FM/ >>> Stephen >>> PSN #55 >> >> >> -- >> No virus found in this outgoing message. >> Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: >> 269.13.35/1039 - Release Date: 9/29/2007 9:46 PM >> >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body >> of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > Wouldn't you know,,  we must have jarred something loose,, ha,,  I just checked and today it is working,,,   thanks to all.
  Stephen
  PSN #55

John Lahr wrote:
Here's the word from the USGS.  Cheers, John

   Because of Department of Interior security requirements, we had to
   install a number of new routers in our internal network. At that point
   some of our processes that depended on communication between different
   subnets stopped working. In other words, some of our programs broke.
   Most of the problems were fixed on the first day, but we are still
   unable to compute the moment tensors.


   We have been working on a new, faster experimental system, with an
   improved user interface, for generating the moment tensors. Since this
   is the direction we were already committed to, we have decided to
   accelerate implementation of the new system. In the near future we hope
   to be computing moment tensors again, using the new system.


   You may want to take a look at the USGS Earthquake Notification Service
   (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These notifications,
   at this time, will not include the "beachball", but will be A LOT
   faster. They are also very easy to customize in terms of geographic
   region(s) of interest and magnitude threshold. You may end up preferring
   these to the moment tensor solutions.






At 04:47 PM 9/30/2007, you wrote:
Hi Stephen,
                  yeah damn annoying,   some weeks ago I emailed Madelene Zirbies
 who is one of the ones looking after the www site.   She was aware of it and
seemed to indicate that it wasnt going to get fixed any time soon.

 the other data available  under the Scientific & Technical tab  just
isnt the same  :(  for one  it doesnt have the nice world map  image with the
"beachball" on it that I had saved on puter for many years.   also the data is in
a different format.  also the  "Global CMT Project Moment Tensor Solution"  info
now being supplied  lists events Mw6.0 and higher  and some times only the high
events  eg  M6.6 up

cheers
Dave N
Sydney



At 11:27 AM 9/30/2007 -0700, you wrote:
Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007?
I know that I can get the info in a few days under the Scientific & Technical tab of the individual quakes at NEIC, but was wondering what happened to their FM Tensor list at the following link???
<http://neic.usgs.gov/neis/FM/>http://neic.usgs.gov/neis/FM/
 Stephen
 PSN #55


--
No virus found in this outgoing message.
Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.35/1039 - Release Date: 9/29/2007 9:46 PM


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

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See http://www.seismicnet.com/maillist.html for more information.



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Subject: San Andreas drilling From: ian ian@........... Date: Sat, 06 Oct 2007 09:05:08 +0100 interesting story about recovering rocks from deep inside the fault: http://news.bbc.co.uk/2/hi/science/nature/7030660.stm Ian __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: WinQuake Display Question From: "Jerry Payton" gpayton880@....... Date: Tue, 9 Oct 2007 14:01:05 -0500 (Question 1): On a WinQuake event display are the P and S arrival times showning the ACTUAL arrival times or shown according to what the table says they should be? (Question 2): Is the distance from the event to your seismograph computed "through the earth" or "around the surface?" Thank you, Jerry Payton
(Question 1):    On a WinQuake event display = are the=20 P and S arrival times showning the ACTUAL arrival times = or=20 shown according to what the table says they should be?
 
(Question 2):    Is the distance from the event to=20 your seismograph computed "through the earth" or "around the=20 surface?"
 
Thank you,
Jerry Payton
 
 
 
 
Subject: Re: WinQuake Display Question From: tchannel1@............ Date: Tue, 9 Oct 2007 14:55:46 -0600 Hi Jerry, "I Think"................Q 1 The p and s and other = phases if you use them are all based on (time theory) =20 The math program knows where you are and where the event took place, it = converts that info to Miles, also to Degrees. It then uses one of several formulas, I use the default formula, to = place the p and s on a time line, which is on the bottom of the Winquake = screen. Q2.........The distance is "around the surface" like a string on a = globe. This is all "great circle" math. So the program is simple for this part, because, it take the event Long. = and Lat, your Long. and Lat, the time of the event, does the math (the = p travels about 10km per second), I calculate it is about 28,000 miles = per hour, and figure it would take the P, say 12.002 minute to reach = you, add that, to the event time, and places the P on your screen = accordingly. It does not read you recording, you could have recorded a truck or a = train and if the event matched your train in would place the p and s, on = the time line. Is this clear??????????????????? Ted ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Tuesday, October 09, 2007 1:01 PM Subject: WinQuake Display Question (Question 1): On a WinQuake event display are the P and S arrival = times showning the ACTUAL arrival times or shown according to what the = table says they should be? (Question 2): Is the distance from the event to your seismograph = computed "through the earth" or "around the surface?" Thank you, Jerry Payton
Hi Jerry,  "I = Think"................Q=20 1        The p and s and other phases = if you=20 use them are all based on (time theory)  
The math program knows where you are = and where the=20 event took place, it converts that info to Miles, also to = Degrees.
It then uses one of several = formulas, I use=20 the default formula, to place the p and s on a time line, which is = on the=20 bottom of the Winquake screen.
 
Q2.........The distance is "around the = surface"=20 like a string on a globe.   This is all "great circle"=20 math.
 
So the program is simple for this part, = because, it=20 take the event Long. and Lat,  your Long. and Lat, the time of the = event,=20 does the math (the p travels about 10km per second), I calculate it is = about=20 28,000 miles per hour, and figure it would take the P, say  12.002 = minute=20 to reach you, add that, to the event time, and places the P on your = screen=20 accordingly.
 
It does not read you recording,  = you could=20 have recorded a truck or a train and if the event matched your train in = would=20 place the p and s, on the time line.
 
Is this = clear???????????????????  =20 Ted
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Tuesday, October 09, 2007 = 1:01=20 PM
Subject: WinQuake Display = Question

(Question 1):    On a WinQuake event display = are the=20 P and S arrival times showning the ACTUAL arrival = times or=20 shown according to what the table says they should be?
 
(Question 2):    Is the distance from the event to = your seismograph computed "through the earth" or "around the=20 surface?"
 
Thank you,
Jerry Payton
 
 
 
 
Subject: Re: WinQuake Display Question From: "Jerry Payton" gpayton880@....... Date: Tue, 9 Oct 2007 16:46:17 -0500 Yes, you answer IS clear. I suspected that it was a "Great Circle" measurement, but wanted verification. However, I was curious about the phase-time travel. Wave propagation through the earth is a highly variable thing depending upon the materials it travels through, reflections, refractions and etc. I guess that the "tables" are basically averages taken from measurements over the years and reasonably accurate. What prompted my question was reading about the construction of the "beachball" Focal Mechanism Solution. They look at the P wave arrival and depending upon whether it goes up or down determines one of the factors of the final solution. Thus, exact timing is needed. If the P wave is arbitrarily identified, the solution would be false. (I think???) Thank you, Jerry ----- Original Message ----- From: tchannel1@............ To: psn-l@.............. Sent: Tuesday, October 09, 2007 3:55 PM Subject: Re: WinQuake Display Question Hi Jerry, "I Think"................Q 1 The p and s and other phases if you use them are all based on (time theory) The math program knows where you are and where the event took place, it converts that info to Miles, also to Degrees. It then uses one of several formulas, I use the default formula, to place the p and s on a time line, which is on the bottom of the Winquake screen. Q2.........The distance is "around the surface" like a string on a globe. This is all "great circle" math. So the program is simple for this part, because, it take the event Long. and Lat, your Long. and Lat, the time of the event, does the math (the p travels about 10km per second), I calculate it is about 28,000 miles per hour, and figure it would take the P, say 12.002 minute to reach you, add that, to the event time, and places the P on your screen accordingly. It does not read you recording, you could have recorded a truck or a train and if the event matched your train in would place the p and s, on the time line. Is this clear??????????????????? Ted ----- Original Message ----- From: Jerry Payton To: psn-l@.............. Sent: Tuesday, October 09, 2007 1:01 PM Subject: WinQuake Display Question (Question 1): On a WinQuake event display are the P and S arrival times showning the ACTUAL arrival times or shown according to what the table says they should be? (Question 2): Is the distance from the event to your seismograph computed "through the earth" or "around the surface?" Thank you, Jerry Payton
Yes, you answer IS clear.  I suspected that it was a "Great = Circle"=20 measurement, but wanted verification.
 
However, I was curious about the phase-time travel.  Wave = propagation=20 through the earth is a highly variable thing depending upon the = materials it=20 travels through, reflections, refractions and etc.  I guess that = the=20 "tables" are basically averages taken from measurements over the years = and=20 reasonably accurate.
 
What prompted my question was reading about the construction = of the=20 "beachball" Focal Mechanism Solution.  They look at the P wave = arrival and=20 depending upon whether it goes up or down determines one of the factors = of the=20 final solution.  Thus, exact timing is needed.  If the P wave = is=20 arbitrarily identified, the solution would be false.  (I = think???)
 
Thank you,
Jerry
 
 
----- Original Message -----=20
From: tchannel1@............
Sent: Tuesday, October 09, 2007 3:55 PM
Subject: Re: WinQuake Display Question

Hi Jerry,  "I = Think"................Q=20 1        The p and s and other phases = if you=20 use them are all based on (time theory)  
The math program knows where you are = and where the=20 event took place, it converts that info to Miles, also to = Degrees.
It then uses one of several = formulas, I use=20 the default formula, to place the p and s on a time line, which is = on the=20 bottom of the Winquake screen.
 
Q2.........The distance is "around the = surface"=20 like a string on a globe.   This is all "great circle"=20 math.
 
So the program is simple for this part, = because, it=20 take the event Long. and Lat,  your Long. and Lat, the time of the = event,=20 does the math (the p travels about 10km per second), I calculate it is = about=20 28,000 miles per hour, and figure it would take the P, say  12.002 = minute=20 to reach you, add that, to the event time, and places the P on your = screen=20 accordingly.
 
It does not read you recording,  = you could=20 have recorded a truck or a train and if the event matched your train in = would=20 place the p and s, on the time line.
 
Is this = clear???????????????????  =20 Ted
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Tuesday, October 09, 2007 = 1:01=20 PM
Subject: WinQuake Display = Question

(Question 1):    On a WinQuake event display = are the=20 P and S arrival times showning the ACTUAL arrival = times or=20 shown according to what the table says they should be?
 
(Question 2):    Is the distance from the event to = your seismograph computed "through the earth" or "around the=20 surface?"
 
Thank you,
Jerry Payton
 
 
 
 
Subject: Re: WinQuake Display Question From: Bob Hancock carpediem1@......... Date: Tue, 09 Oct 2007 17:24:42 -0700 There are both body waves which travel through the earth=B9s mantel and core, and surface waves which follow the crust. The P & S waves and their variations are body waves. The LQ and LR waves are surface waves and follo= w the surface of the earth. These waves also have different dissipation rates.=20 Alan Jones program Seismic Waves gives a good presentation of the major waves. You can download it from the following link: http://www.geol.binghamton.edu/faculty/jones/ Using WinQuake, the wave arrival times are computed based upon standard wav= e speeds depending upon the route the waves take, and the depth of the event. The data is computed using the latitude and longitude of the event and the station recording the event. Bob Hancock On 10/9/07 2:46 PM, "Jerry Payton" wrote: > Yes, you answer IS clear. I suspected that it was a "Great Circle" > measurement, but wanted verification. > =20 > However, I was curious about the phase-time travel. Wave propagation thr= ough > the earth is a highly variable thing depending upon the materials it trav= els > through, reflections, refractions and etc. I guess that the "tables" are > basically averages taken from measurements over the years and reasonably > accurate. > =20 > What prompted my question was reading about the construction of the > "beachball" Focal Mechanism Solution. They look at the P wave arrival an= d > depending upon whether it goes up or down determines one of the factors o= f the > final solution. Thus, exact timing is needed. If the P wave is arbitrar= ily > identified, the solution would be false. (I think???) > =20 > Thank you, > Jerry > =20 > =20 > ----- Original Message ----- > From: tchannel1@............ > To: psn-l@.............. > Sent: Tuesday, October 09, 2007 3:55 PM > Subject: Re: WinQuake Display Question >=20 > Hi Jerry, "I Think"................Q 1 The p and s and other phas= es if > you use them are all based on (time theory) > The math program knows where you are and where the event took place, it > converts that info to Miles, also to Degrees. > It then uses one of several formulas, I use the default formula, to place= the > p and s on a time line, which is on the bottom of the Winquake screen. > =20 > Q2.........The distance is "around the surface" like a string on a globe. > This is all "great circle" math. > =20 > So the program is simple for this part, because, it take the event Long. = and > Lat, your Long. and Lat, the time of the event, does the math (the p tra= vels > about 10km per second), I calculate it is about 28,000 miles per hour, an= d > figure it would take the P, say 12.002 minute to reach you, add that, to= the > event time, and places the P on your screen accordingly. > =20 > It does not read you recording, you could have recorded a truck or a tra= in > and if the event matched your train in would place the p and s, on the ti= me > line. > =20 > Is this clear??????????????????? Ted >> =20 >> ----- Original Message ----- >> =20 >> From: Jerry Payton >> =20 >> To: psn-l@.............. >> =20 >> Sent: Tuesday, October 09, 2007 1:01 PM >> =20 >> Subject: WinQuake Display Question >> =20 >>=20 >> =20 >> (Question 1): On a WinQuake event display are the P and S arrival ti= mes >> showning the ACTUAL arrival times or shown according to what the table = says >> they should be? >> =20 >> =20 >> =20 >> (Question 2): Is the distance from the event to your seismograph com= puted >> "through the earth" or "around the surface?" >> =20 >> =20 >> =20 >> Thank you, >> =20 >> Jerry Payton >> =20 >> =20 >> =20 >> =20 >> =20 >> =20 >> =20 >> =20 >=20 Re: WinQuake Display Question There= are both body waves which travel through the earth’s mantel and core,= and surface waves which follow the crust.  The P & S waves and the= ir variations are body waves.  The LQ and LR waves are surface waves an= d follow the surface of the earth.  These waves also have different dis= sipation rates.

Alan Jones program Seismic Waves gives a good presentation of the major wav= es.  You can download it from the following link:

        http://www.geol.binghamton.edu/faculty/jones/

Using WinQuake, the wave arrival times are computed based upon standard wav= e speeds depending upon the route the waves take, and the depth of the event= ..

The data is computed using the latitude and longitude of the event and the = station recording the event.

Bob Hancock


On 10/9/07 2:46 PM, "Jerry Payton" <gpayton880@.......> wro= te:

Yes, you answer IS clear.  I suspected that it was= a "Great Circle" measurement, but wanted verification.
 
However, I was curious about the phase-time travel.  Wave propagation = through the earth is a highly variable thing depending upon the materials it= travels through, reflections, refractions and etc.  I guess that the &= quot;tables" are basically averages taken from measurements over the ye= ars and reasonably accurate.
 
What prompted my question was reading about the construction of the "b= eachball" Focal Mechanism Solution.  They look at the P wave arriv= al and depending upon whether it goes up or down determines one of the facto= rs of the final solution.  Thus, exact timing is needed.  If the P= wave is arbitrarily identified, the solution would be false.  (I think= ???)
 
Thank you,
Jerry
 
 
----- Original Message -----
From: tchannel1@............
To: psn-l@..............
Sent: Tuesday, October 09, 2007 3:55 PM
Subject: Re: WinQuake Display Question

Hi Jerry, &= nbsp;"I Think"................Q 1      &n= bsp; The p and s and other phases if you use them are all based on (tim= e theory)   
The math program knows where you are and where the event took place, it con= verts that info to Miles, also to Degrees.
It then uses one of several formulas, I use the default formula, to place t= he p and s on a time line, which is on the bottom of the Winquake screen.
Q2.........The distance is "around the surfa= ce" like a string on a globe.   This is all "great circl= e" math.
So the program is simple for this part, because, = it take the event Long. and Lat,  your Long. and Lat, the time of the e= vent, does the math (the p travels about 10km per second), I calculate it is= about 28,000 miles per hour, and figure it would take the P, say  12.0= 02 minute to reach you, add that, to the event time, and places the P on you= r screen accordingly.
It does not read you recording,  you could h= ave recorded a truck or a train and if the event matched your train in would= place the p and s, on the time line.
Is this clear???????????????????   Ted<= BR>

----- Original Message -----
 
From:  Jerry Payton <mai= lto:gpayton880@.......>   
 
To: psn-l@..............
 
Sent: Tuesday, October 09, 2007 1:01  PM
 
Subject: WinQuake Display Question
 

 
(Question 1):    On a WinQuake event display are the  P= and S arrival times showning the ACTUAL arrival times or  shown= according to what the table says they should be?
 
 
 
(Question 2):    Is the distance from the event to  you= r seismograph computed "through the earth" or "around the &nb= sp;surface?"
 
 
 
Thank you,
 
Jerry Payton
 
 
 
 
 
 
 
 


 Subject: Re: WinQuake Display Question From: ChrisAtUpw@....... Date: Tue, 9 Oct 2007 20:50:59 EDT In a message dated 09/10/2007 22:46:38 GMT Daylight Time, gpayton880@....... writes: Wave propagation through the earth is a highly variable thing depending upon the materials it travels through, reflections, refractions and etc. I guess that the "tables" are basically averages taken from measurements over the years and reasonably accurate. The wave velocities are mostly determined by depth, so it is possible to plot average curves for the time travel along the curved ray paths. You may also have to allow for the depth of the quake. Seismic Waves and Seismic Eruptions give good visualisation of the principle waves. See Alan Jones website at _http://www.geol.binghamton.edu/faculty/jones/_ (http://www.geol.binghamton.edu/faculty/jones/) Regards, Chris Chapman
In a message dated 09/10/2007 22:46:38 GMT Daylight Time,=20 gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000>Wave=20 propagation through the earth is a highly variable thing depending upon th= e=20 materials it travels through, reflections, refractions and etc.  I gu= ess=20 that the "tables" are basically averages taken from measurements over the=20 years and reasonably accurate.
    The wave velocities are mostly determined by de= pth,=20 so it is possible to plot average curves for the time travel along the curve= d=20 ray paths. You may also have to allow for the depth of the quake.
 
    Seismic Waves and Seismic=20 Eruptions give good visualisation of the principle waves.  See Alan Jon= es=20 website at http://www.geol.binghamton.edu/faculty/jones/
    Regards,
 
    Chris Chapman
Subject: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Tue, 9 Oct 2007 19:28:02 -0600 Hi all, I think it might be fun for those of you who are amateur or real "engineers"; to come up with their own thoughts and use/s for acouple pictures of a item at: http://home.earthlink.net/~meredithlamb/ I have my own (surprising) and varied uses in mind; whats yours? Meredith Lamb
Hi all,
 
I think it might be fun for those of you who are amateur or real "engineers";
to come up with their own thoughts and use/s for acouple pictures of a item at:
 
 
I have my own (surprising) and varied uses in mind; whats yours?
 
Meredith Lamb
 
 
Subject: Travel times From: "Randy Pratt" rpratt@............. Date: Wed, 10 Oct 2007 17:28:44 -0500 Hi All, I saw the question on travel times and had just come across this page a couple nights back showing some plots of times and locations. http://aslwww.cr.usgs.gov/Seismic_Data/ttdata.shtml Randy
Hi=20 All,
 
I saw = the question=20 on travel times and had just come across this page a couple nights back = showing=20 some plots of times and locations.
 
http://aslww= w.cr.usgs.gov/Seismic_Data/ttdata.shtml
 
Randy
Subject: seismometer/site sensitivity From: Jan Froom JDarwin@............. Date: Thu, 11 Oct 2007 12:35:32 -0700 I'm curious how many of you have come up with a "rule of thumb" for the general sensitivity of your seismometers. For instance I have sensed a 3.0 sixty miles out from my seismometer, and have seen 5s within 300 miles. And I understand we should be able to sense a 7 anywhere in the world. But just now, I did not see a 1.3 seven miles out. So my question.... is this good, bad, average? I'm sure there are lots of variables such as type of instrument, orientation, ambient noise, etc.. but still, shouldn't there be a general feeling or rule of thumb. Jan in Gilroy I'm curious how many of you have come up with a "rule of thumb" for the general sensitivity of your seismometers.

For instance I have sensed a 3.0 sixty miles out from my seismometer, and have seen 5s within 300 miles.
And I understand we should be able to sense a 7 anywhere in the world.
But just now, I did not see a 1.3  seven miles out.
So my question.... is this good, bad, average?
I'm sure there are lots of variables such as type of instrument, orientation, ambient noise, etc..
but still, shouldn't there be a general feeling or rule of thumb.

Jan in Gilroy
Subject: Re: seismometer/site sensitivity From: Pete Rowe ptrowe@......... Date: Thu, 11 Oct 2007 12:45:49 -0700 (PDT) Hi Jan I'd say that you are doing just fine. With my 3 second period horizontal I see 5s down in Mexico, 7s anywhere, but a 1.3 needs to be with in 3 or 4 miles. I have never gone to the trouble of actually trying to calibrate mine because I really don't know how to do it and haven't taken the time to learn. The gain numbers that I use in Larry's program are just guesses. 73, Pete --- Jan Froom wrote: > I'm curious how many of you have come up with a > "rule of thumb" for the > general sensitivity of your seismometers. > > For instance I have sensed a 3.0 sixty miles out > from my seismometer, > and have seen 5s within 300 miles. > And I understand we should be able to sense a 7 > anywhere in the world. > But just now, I did not see a 1.3 seven miles out. > So my question.... is this good, bad, average? > I'm sure there are lots of variables such as type of > instrument, > orientation, ambient noise, etc.. > but still, shouldn't there be a general feeling or > rule of thumb. > > Jan in Gilroy > ____________________________________________________________________________________ Tonight's top picks. What will you watch tonight? Preview the hottest shows on Yahoo! TV. http://tv.yahoo.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 11 Oct 2007 20:46:58 +0000 Hi Small earthquakes can be difficault to detect. But for me the general rule is that the less background noise there is, the bigger the chance of seeing small earthquake is. More background noise, less chance. I have seen earthquakes down to 1.0 or smaller up to a distance of ~55 km. After that, it is really a hard to see small earthquakes. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: Larry Conklin lconklin@............ Date: Thu, 11 Oct 2007 17:28:01 -0400 I have a spreadsheet that I have been using for several years to log the events that I've been able to record. It includes a scatterplot of magnitude versus distance. In addition, I assign a rough "quality" score to the events (A - D) that is used to determine the color of the points plotted. I live in central NY, so the vast majority of events that I see are at teleseismic distances, and frustratingly, a very high percentage of the stuff I see is at distances that put me in the shadow zone. I am very definitely limited by some mix of environmental noise and very possibly some sort of spruious system noise that I don't really understand. If anyone is interested in seeing my accumulated results, I would be happy to send them a copy of the spreadsheet. Larry Conklin Liverpool, NY lconklin@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: "Geoff" gmvoeth@........... Date: Fri, 12 Oct 2007 02:15:00 -0700 I have a vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2 volts per inches per second and I can see a magnitude 4 about 6 degrees away. or so it seems. I am using heavy damping to allow me to use a single bandpass filter to equalize the freq response of a one hertz geophone somewhere between 4 seconds and 2 Hz. The geophone is buried underground on a granite tile with the base of the geophone maybe 24 inches below ground. Sealed to the best of my abilities against temp and moisture and electro/magnetic fields. My area here is extremely noisy from vehicular traffic as well as electrical disturbances. My station is not a very good one but will at least let me know when a major event happens. The USGS was not interested in signals from this station unless my times were the very first and that is so very rare. Commonly the local signals are mine blasts which they seem to have no interest in also. The USGS seems to have there own setup that does not seem to miss anything at all. You need a friend there to look for signals you might see at your amature station that are not earth quakes. They are busy people there i believe with no lower level help doing any analysis. You most probably shall have troubles identifying small stuff since you need several signatures to compare. You got to compare your signals with the USGS to get an idea what your MDL ( minimum dicernable level) really is. It will take time. ----- Original Message ----- From: "Jan Froom" To: Sent: Thursday, October 11, 2007 12:35 PM Subject: seismometer/site sensitivity > I'm curious how many of you have come up with a "rule of thumb" for the > general sensitivity of your seismometers. > > For instance I have sensed a 3.0 sixty miles out from my seismometer, > and have seen 5s within 300 miles. > And I understand we should be able to sense a 7 anywhere in the world. > But just now, I did not see a 1.3 seven miles out. > So my question.... is this good, bad, average? > I'm sure there are lots of variables such as type of instrument, > orientation, ambient noise, etc.. > but still, shouldn't there be a general feeling or rule of thumb. > > Jan in Gilroy > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: ChrisAtUpw@....... Date: Fri, 12 Oct 2007 07:07:11 EDT In a message dated 12/10/2007, gmvoeth@........... writes: I have a vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2 volts per inches per second and I can see a magnitude 4 about 6 degrees away. or so it seems. I am using heavy damping to allow me to use a single bandpass filter to equalize the freq response of a one hertz geophone somewhere between 4 seconds and 2 Hz. Hi Geoff, You need to use negative impedance input to get broad band response from a geophone by heavy damping to mostly cancel out the internal resistance. You then need a very low noise 1/f amplifier to give you a flat to velocity response. The technique is dscribed with references at _http://www.lennartz-electronic.de/MamboV4.5.2/downloads/Seismometers.pdf_ (http://www.lennartz-electronic.de/MamboV4.5.2/downloads/Seismometers.pdf) Regards, Chris Chapman
In a message dated 12/10/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have a=20 vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2=20 volts per inches per second and I can see a magnitude 4 about 6 degrees aw= ay.=20 or so it seems. I am using heavy damping to allow me to use a single bandp= ass=20 filter to equalize the freq response of a one hertz geophone somewher= e=20 between 4 seconds and 2 Hz.
 
Hi Geoff,
 
    You need to use negative impedance input to get= =20 broad band response from a geophone by heavy damping to mostly cancel out th= e=20 internal resistance. You then need a very low noise 1/f amplifier to give yo= u a=20 flat to velocity response.
    The technique is dscribed with references at http://www.lennartz-electronic.de/MamboV4.5.2/downloads/Seismometers.p= df
 
    Regards,
 
    Chris Chapman
Subject: Re: seismometer/site sensitivity From: "Connie and Jim Lehman" lehmancj@........... Date: Fri, 12 Oct 2007 11:27:14 -0400 Jan. I believe your system is in the "ball-park" in performance. I = don't know what design you are working with, or your exact location. = With our experience with a long-period cantilever (l8 sec) period, we = generally read 3.0 events --here in Virginia, some quarry blasts, not = many natural events here!. Anything Mag. 5 and above in the U.S. = Alaska, and much of Central and South America. Anything Mag.. 6 or more = worldwide. Of course events in South Pacific outnumbered the rest of = the World for us. The ideal was when we ran two identical sensors = broadside N-S and E-W. We generally let microseisms decide the = amplitude setting. In our summertime here in VA. the microseisms are = lower (for whatever reasons??) and we could crank up the daily gains, = and for a two month summer recording with two sensors we received our = record of 62 events in 60 days. That was years ago, and I haven't tried = a repeat. Best wishes, Jim Lehman ----- Original Message -----=20 From: Jan Froom=20 To: psn-l@................. Sent: Thursday, October 11, 2007 3:35 PM Subject: seismometer/site sensitivity I'm curious how many of you have come up with a "rule of thumb" for = the general sensitivity of your seismometers. For instance I have sensed a 3.0 sixty miles out from my seismometer, = and have seen 5s within 300 miles. And I understand we should be able to sense a 7 anywhere in the world. But just now, I did not see a 1.3 seven miles out. So my question.... is this good, bad, average?=20 I'm sure there are lots of variables such as type of instrument, = orientation, ambient noise, etc..=20 but still, shouldn't there be a general feeling or rule of thumb. Jan in Gilroy
Jan.  I believe your system is in = the=20 "ball-park" in performance.  I don't know what design you are = working with,=20 or your exact location.  With our experience with a long-period = cantilever=20 (l8 sec) period, we generally read 3.0 events --here in Virginia, some = quarry=20 blasts, not many natural events here!.  Anything Mag. 5 and above = in the=20 U.S. Alaska, and much of Central and South America.  = Anything=20 Mag.. 6 or more worldwide.   Of course events in South Pacific = outnumbered the rest of the World for us.  The ideal was when = we=20 ran two identical sensors broadside N-S and E-W.  We generally = let=20 microseisms decide the amplitude setting.  In our summertime here = in VA.=20 the microseisms are lower (for whatever reasons??) and we could crank up = the=20 daily gains, and for a two month summer recording with two sensors we = received=20 our record of 62 events in 60 days.  That was years ago, and I = haven't=20 tried a repeat.
        =20 Best wishes,    Jim Lehman
----- Original Message -----
From:=20 Jan=20 Froom
Sent: Thursday, October 11, = 2007 3:35=20 PM
Subject: seismometer/site=20 sensitivity

I'm curious how many = of you=20 have come up with a "rule of thumb" for the general sensitivity of = your=20 seismometers.

For instance I have sensed a 3.0 sixty miles out = from my=20 seismometer, and have seen 5s within 300 miles.
And I understand we = should=20 be able to sense a 7 anywhere in the world.
But just now, I did not = see a=20 1.3  seven miles out.
So my question.... is this good, bad, = average?=20
I'm sure there are lots of variables such as type of instrument,=20 orientation, ambient noise, etc..
but still, shouldn't there be a = general=20 feeling or rule of thumb.

Jan in=20 Gilroy
Subject: Re: seismometer/site sensitivity From: Bobhelenmcclure@....... Date: Sat, 13 Oct 2007 21:29:59 EDT Hi Geoff, There is a better way to extend the response of a 1 Hz geophone, or any open loop sensor. Try the period extending filter in WQFilter.exe. Use normal damping. The filter can extend the period by a factor of 8 or more on major events. This is a digital inverse filter, whose gain is shaped to preserve normal gain at high frequencies and to supply the gain needed at frequencies below the natural frequency of the sensor. The utility can be downloaded from _http://www.jclahr.com/science/psn/mcclure/sac/index.html_ (http://www.jclahr.com/science/psn/mcclure/sac/index.html) This program includes high-pass and low-pass Butterworth filters which perform better than those supposedly IIR BW filters in WinQuake. I have learned never to use WinQuake's filters. I use the lowest order, order 2, both directions for high-pass filtering. Extended period filtering works best if you select the option "LONG PERIOD plus HPF". Additional high-pass filtering is usually unnecessary if you use that option. Even long period period Lehman sensors can benefit from proper use of WQFilter, as it can compensate for over- or under-damping. It can make the filtered long period response either longer or shorter than the actual sensor period. On an unrelated note, those of you who use HP calculators with Reverse Polish Notation will like the following freeware calculator for your PC desktop: _http://www.tordivel.no/xcalc/_ (http://www.tordivel.no/xcalc/) Bob In a message dated 12/10/2007, gmvoeth@.... writes: I have a vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2 volts per inches per second and I can see a magnitude 4 about 6 degrees away. or so it seems. I am using heavy damping to allow me to use a single bandpass filter to equalize the freq response of a one hertz geophone somewhere between 4 seconds and 2 Hz. ************************************** See what's new at http://www.aol.com
Hi Geoff,
 
  There is a better way to extend the response of a 1 Hz geophone,= or=20 any open loop sensor. Try the period extending filter in WQFilter.exe. Use=20 normal damping. The filter can extend the period by a factor of 8 or more on= =20 major events. This is a digital inverse filter, whose gain is shaped to pres= erve=20 normal gain at high frequencies and to supply the gain needed at frequencies= =20 below the natural frequency of the sensor. The utility can be downloaded=20 from
 
   http://www= ..jclahr.com/science/psn/mcclure/sac/index.html
 
  This program includes high-pass and low-pass Butterworth filters= =20 which perform better than those supposedly IIR BW filters in WinQuake. I hav= e=20 learned never to use WinQuake's filters. I use the lowest order, order 2, bo= th=20 directions for high-pass filtering. Extended period filtering works bes= t if=20 you select the option "LONG PERIOD plus HPF". Additional high-pass filtering= is=20 usually unnecessary if you use that option. Even long period period Lehman=20 sensors can benefit from proper use of WQFilter, as it can compensate for ov= er-=20 or under-damping. It can make the filtered long period response either longe= r or=20 shorter than the actual sensor period.
 
  On an unrelated note, those of you who use HP calculators with=20 Reverse Polish Notation will like the following freeware calculator for your= PC=20 desktop:
 
 http://www.tordivel.no/xcalc/
 
Bob
 
In a message dated 12/10/2007, gmvoeth@.... writes:
 
I have a  vertical setup with a sensor that seems to have a=20 sensitivity of
1.5 to 2  volts per inches per second and I can see=20= a=20 magnitude 4 about 6
degrees away.  or so it seems. I am using heavy= =20 damping to allow me to use a single
bandpass  filter to equalize th= e=20 freq response of a one hertz geophone
somewhere  between 4 seconds=20= and=20 2 Hz.



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= Subject: Earthquake near Albany, NY, U.S ? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 14 Oct 2007 14:36:34 +0000 Hi all I have a friend how lives in Albany, N.Y in the U.S. He tells me that he felt two earthquake like shocks around 2 am local time, they where each with about five min, intervals. I did look for earthquakes on the usgs web page but I didn't find anything there. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: Stephen & Kathy skmort@............ Date: Sun, 14 Oct 2007 08:24:59 -0700 If we are talking about this morning, about 6:00 UTC, I see nothing on = the N/E USA webicorders??? http://aslwww.cr.usgs.gov/Seismic_Data/heli2_us.shtml Stephen J=F3n Fr=EDmann wrote: > Hi all > > I have a friend how lives in Albany, N.Y in the U.S. He tells me that h= e > felt two earthquake like shocks around 2 am local time, they where each= > with about five min, intervals. > > I did look for earthquakes on the usgs web page but I didn't find > anything there. > > Regards. > =20 If we are talking about this morning,=A0 about 6:00= UTC,=A0 I see nothing on the N/E USA webicorders???

http://aslwww.cr.usgs.gov/Seismic_Data/heli2_us.= shtml
=A0 Stephen

J=F3n Fr=EDmann wrote: 
Hi all

I have a friend how lives in Albany, N.Y in the U.S. He tells me that he
felt two earthquake like shocks around 2 am local time, they where each
with about five min, intervals.

I did look for earthquakes on the usgs web page but I didn't find
anything there.

Regards.
Subject: Re: Earthquake near Albany, NY, U.S ? From: Bob Hancock carpediem1@......... Date: Sun, 14 Oct 2007 08:43:02 -0700 Hi Jon - Here is a link to the other stations at Lamont-Daugherty. Click on station HCNY. It is located about 30 miles west of Albany, NY, and UTC time is located on the right side of the chart. http://www.ldeo.columbia.edu/LCSN/view_pal.html Bob Hancock On 10/14/07 7:36 AM, "J=F3n Fr=EDmann" wrote: > Hi all >=20 > I have a friend how lives in Albany, N.Y in the U.S. He tells me that he > felt two earthquake like shocks around 2 am local time, they where each > with about five min, intervals. >=20 > I did look for earthquakes on the usgs web page but I didn't find > anything there. >=20 > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: "Thomas Dick" dickthomas01@............. Date: Mon, 15 Oct 2007 07:00:15 -0500 Midwest network indicates a 1.5 mag at Tupper Lake NY see at ----- Original Message ----- From: "Bob Hancock" To: Sent: Sunday, October 14, 2007 10:43 AM Subject: Re: Earthquake near Albany, NY, U.S ? Hi Jon - Here is a link to the other stations at Lamont-Daugherty. Click on station HCNY. It is located about 30 miles west of Albany, NY, and UTC time is located on the right side of the chart. http://www.ldeo.columbia.edu/LCSN/view_pal.html Bob Hancock On 10/14/07 7:36 AM, "Jón Frímann" wrote: > Hi all > > I have a friend how lives in Albany, N.Y in the U.S. He tells me that he > felt two earthquake like shocks around 2 am local time, they where each > with about five min, intervals. > > I did look for earthquakes on the usgs web page but I didn't find > anything there. > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: "Thomas Dick" dickthomas01@............. Date: Mon, 15 Oct 2007 07:03:37 -0500 Midwest network shows a 1.5 meg earthquake at Tupper Lake, NY see details at http://folkworm.ceri.memphis.edu/recenteqs/Quakes/quakes0.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: seismometer/site sensitivity From: "Chuck Boudreaux" chuckbou@............. Date: Mon, 15 Oct 2007 10:36:53 -0500 Larry, I would like a copy of the spreadsheet when you get a chance. Chuck Boudreaux Berwick, LA chuckbou@............. -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Larry Conklin Sent: Thursday, October 11, 2007 16:28 To: PSN List Subject: Re: seismometer/site sensitivity I have a spreadsheet that I have been using for several years to log the events that I've been able to record. It includes a scatterplot of magnitude versus distance. In addition, I assign a rough "quality" score to the events (A - D) that is used to determine the color of the points plotted. I live in central NY, so the vast majority of events that I see are at teleseismic distances, and frustratingly, a very high percentage of the stuff I see is at distances that put me in the shadow zone. I am very definitely limited by some mix of environmental noise and very possibly some sort of spruious system noise that I don't really understand. If anyone is interested in seeing my accumulated results, I would be happy to send them a copy of the spreadsheet. Larry Conklin Liverpool, NY lconklin@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: "Thomas Dick" dickthomas01@............. Date: Mon, 15 Oct 2007 14:23:38 -0500 Midwest area recorded two quakes this weekend see http://folkworm.ceri.memphis.edu/recenteqs/Quakes/quakes0.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Octorber From: tchannel1@............ Date: Thu, 18 Oct 2007 09:24:38 -0600 Hi Folks, By my counts, the next two weeks could be very active, or the = month of October is going to be the quietest month this year. Obviously no one can look into the future, but I am convinced the counts = of events do form totals which seem to repeat, month after month. I sure wish I knew more about probabilities, perhaps I could qualify my = observation. My equipment does not record many of the smaller events. = Discounting those smaller events, here are my notes. My monthly average is 16 Lowest month.............12 Highest month............19 October.......................3 If the month of October, DOES play = catch up, the next two weeks are going to be very active. If the month = of October DOESN'T, then please dismiss all of the above as the ranting = of a grumpy old man. Cheers, Ted
Hi Folks,  By my counts, the next = two=20 weeks could be very active, or the month of October is going to be = the=20 quietest month this year.
Obviously no one can look into the = future, but I am=20 convinced the counts of events do form totals which seem to repeat, = month after=20 month.
I sure wish I knew more about = probabilities,=20 perhaps I could qualify my observation.   My equipment does = not record=20 many of the smaller events.  Discounting those smaller events, here = are my notes.
 
My monthly average is 16
Lowest = month.............12
Highest = month............19
October.......................3      = If the=20 month of October, DOES play catch up, the next two weeks are going to be = very=20 active.  If the month of October DOESN'T, then please dismiss all = of the=20 above as the ranting of a grumpy old man.
 
Cheers,
Ted
Subject: Re: Octorber From: Dave Nelson davenn@............... Date: Fri, 19 Oct 2007 06:53:42 +1000 Depends on where you have been living Ted, ;) Down in this part of the world its been VERY active so far this month .... definately the busiest for a long long time. The New Zealand region has truely lived up to its name of " The Shakey Isles" Here's a brief list of the M5+ events.... M5.6 upper Sth Is M5.7 upper Nth Is M5.1 upper Nth Is M54 offshr SW of Sth Is ashk of the M7+ and M6+ events on the last day of the previous month M6.7 Fiordland, Sth Is M6.2 Fiordland, Sth Is M5.8 Fiordland, Sth Is M6.2 Fiordland, Sth Is M5.1 Fiordland, Sth Is M6.5 NW of Raoul Is, to the nth of NZ but well felt in Nth Is. of NZ not to mention the dozens of good aftershocks and other 4.0-4.9 events around the country At 01:24 AM 10/19/2007, you wrote: >Hi Folks, By my counts, the next two weeks could be very active, or the >month of October is going to be the quietest month this year. >Obviously no one can look into the future, but I am convinced the counts >of events do form totals which seem to repeat, month after month. >I sure wish I knew more about probabilities, perhaps I could qualify my >observation. My equipment does not record many of the smaller >events. Discounting those smaller events, here are my notes. > >My monthly average is 16 >Lowest month.............12 >Highest month............19 >October.......................3 If the month of October, DOES play >catch up, the next two weeks are going to be very active. If the month of >October DOESN'T, then please dismiss all of the above as the ranting of a >grumpy old man. > >Cheers, >Ted > > >No virus found in this incoming message. >Checked by AVG Free Edition. >Version: 7.5.488 / Virus Database: 269.15.0/1077 - Release Date: >10/18/2007 9:54 AM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.15.0/1077 - Release Date: 10/18/2007 9:54 AM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Octorber From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 19 Oct 2007 02:57:27 +0000 Hi all In my part of the world, the whole year has been quiet on the earthquake front. Some weeks I don't even record a single earthquake. Regards. -- J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mystery item and its potential seismometry uses/s? From: "Jerry Payton" gpayton880@....... Date: Wed, 24 Oct 2007 10:56:15 -0500 OK, Meredith. I give up and curiosity has got this cat. It reminds me of an oar-lock, but what was you idea? I've seen no replies to your question and there seems to be a lull right now in EQ's. Let's stir up some discussion! Regards, Jerry Payton ----- Original Message ----- From: meredith lamb To: psn-l@.............. Sent: Tuesday, October 09, 2007 8:28 PM Subject: Mystery item and its potential seismometry uses/s? Hi all, I think it might be fun for those of you who are amateur or real "engineers"; to come up with their own thoughts and use/s for a couple pictures of a item at: http://home.earthlink.net/~meredithlamb/ I have my own (surprising) and varied uses in mind; what's yours? Meredith Lamb
OK, Meredith.  I give up and curiosity has got this = cat. =20 It reminds me of an oar-lock, but what was you idea?  I've seen no = replies=20 to your question and there seems to be a lull right now in EQ's.  = Let's=20 stir up some discussion!
Regards,
Jerry Payton
 
----- Original Message -----=20
From: meredith=20 lamb
Sent: Tuesday, October 09, 2007 8:28 PM
Subject: Mystery item and its potential seismometry=20 uses/s?

Hi all,
 
I think it might be fun for those of you who are amateur or real=20 "engineers";
to come up with their own thoughts and use/s for a couple pictures = of a=20 item at:
 
http://home.earthlink.n= et/~meredithlamb/
 
I have my own (surprising) and varied uses in mind; what's = yours?
 
Meredith Lamb
 
 
Subject: Re: Mystery item and its potential seismometry uses/s? From: tchannel1@............ Date: Wed, 24 Oct 2007 11:11:04 -0600 Jerry, You've got that right................This is my slowest month = for a year, day after day very uninteresting screens. Maybe tomorrow? Since I have no earthquakes to discuss...........Could this device be a = support for a large dia. pipe? As a part of a Seismic device, here is my suggestion: Get a large piece of white butcher paper 48" x 48" Draw a center point = on the piece of paper, using a black #2 pencil, connecting two opposite = diagonal corners. Carefully position one corner of the paper facing true north and the = opposite corner south. Place this device in the center of the paper and align it's support = shaft along the N/S axis. Trace the profile of the entire device on to the paper using the black = #2 pencil. Wait for a large earthquake, >7 M, closer than 100 miles. After the large event, retrace the new position of the device's profile, = using a red #2 Pencil. Comparing the original position profile with the new position profile, = one may be able to plot the general direction of the epicenter, and = estimate the magnitude. Unless it move greater than 24" from center. Thanks,=20 Ted ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Wednesday, October 24, 2007 9:56 AM Subject: Re: Mystery item and its potential seismometry uses/s? OK, Meredith. I give up and curiosity has got this cat. It reminds = me of an oar-lock, but what was you idea? I've seen no replies to your = question and there seems to be a lull right now in EQ's. Let's stir up = some discussion! Regards, Jerry Payton ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Tuesday, October 09, 2007 8:28 PM Subject: Mystery item and its potential seismometry uses/s? Hi all, I think it might be fun for those of you who are amateur or real = "engineers";=20 to come up with their own thoughts and use/s for a couple pictures of = a item at: http://home.earthlink.net/~meredithlamb/ I have my own (surprising) and varied uses in mind; what's yours? Meredith Lamb
Jerry,  You've got that=20 right................This is my slowest month for a year, day after day = very=20 uninteresting screens.   Maybe tomorrow?
Since I have no earthquakes to=20 discuss...........Could this device be a support for a large dia.=20 pipe?
 
As a part of a Seismic device, here is = my=20 suggestion:
Get a large piece of white butcher = paper 48" x 48"=20 Draw a center point on the piece of paper, using a black #2 pencil, = connecting=20 two opposite diagonal corners.
Carefully position one corner of the = paper facing=20 true north and the opposite corner south.
Place this device in the center of the = paper and=20 align it's support shaft along the N/S axis.
Trace the profile of the entire device = on to the=20 paper using the black #2 pencil.
 
Wait for a large earthquake, >7 M, = closer than=20 100 miles.
After the large event, retrace the new = position of=20 the device's profile, using a red #2 Pencil.
Comparing the original = position profile with=20 the new position profile, one may be able to plot the general = direction of=20 the epicenter, and estimate the magnitude.  Unless it move greater = than 24"=20 from center.
Thanks,
Ted
 
 
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Wednesday, October 24, = 2007 9:56=20 AM
Subject: Re: Mystery item and = its=20 potential seismometry uses/s?

OK, Meredith.  I give up and curiosity has got this=20 cat.  It reminds me of an oar-lock, but what was you idea?  = I've=20 seen no replies to your question and there seems to be a lull right = now in=20 EQ's.  Let's stir up some discussion!
Regards,
Jerry Payton
 
----- Original Message -----=20
From: meredith=20 lamb
Sent: Tuesday, October 09, 2007 8:28 PM
Subject: Mystery item and its potential seismometry=20 uses/s?

Hi all,
 
I think it might be fun for those of you who are amateur or real=20 "engineers";
to come up with their own thoughts and use/s for a couple = pictures of a=20 item at:
 
http://home.earthlink.n= et/~meredithlamb/
 
I have my own (surprising) and varied uses in mind; what's = yours?
 
Meredith Lamb
 
 
Subject: Re: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Wed, 24 Oct 2007 20:09:43 -0600 Hi Jerry and all, I put up some text and 3 more pictures of a rather unusual pendulum (horizontal sensing), on the web, and some very brief text relating to its other vertical sensing use/s. The pendulum is essentially a hanging mass or "S-G" type. The aluminum looks to be quite useful for a variety of seismometer setups....without...as much material being used. Fun stuff! See: http://home.earthlink.net/~meredithlamb/ Take care, Meredith Lamb On 10/24/07, Jerry Payton wrote: > > *OK, Meredith. I give up and curiosity has got this cat. It reminds me > of an oar-lock, but what was you idea? I've seen no replies to your > question and there seems to be a lull right now in EQ's. Let's stir up some > discussion!* > *Regards,* > *Jerry Payton* > ** >
Hi Jerry and all,
 
I put up some text and 3 more pictures of a rather unusual pendulum (horizontal
sensing), on the web, and some very brief text relating to its other vertical sensing
use/s.  The pendulum is essentially a hanging mass or "S-G" type.  The aluminum
looks to be quite useful for a variety of seismometer setups....without...as much
material being used.  Fun stuff!  See:
 
 
Take care, Meredith Lamb

 
On 10/24/07, Jerry Payton <gpayton880@.......> wrote:
OK, Meredith.  I give up and curiosity has got this cat.  It reminds me of an oar-lock, but what was you idea?  I've seen no replies to your question and there seems to be a lull right now in EQ's.  Let's stir up some discussion!
Regards,
Jerry Payton
 
Subject: RE: Mystery item and its potential seismometry uses/s? From: "Steve Hammond" shammon1@............. Date: Wed, 24 Oct 2007 23:24:27 -0700 Hi, The design suggests to me that it may have been connected to a round object such as a sailboat's mast. I once read about a counter balance = device that reduced the port/starboard sway when a boat is at anchor buy using = a counterbalance pendulum to create an apposing force that reduces the = wave energy. The rollers in the top photo suggest to me that they would allow = the base object to be hoisted to the upper portion of a mast increasing the effect of the pendulum. Here is a link to some patents that describe = this idea. www.freepatentsonline.com/CCL-114-122.html=20 =20 My guess, Steve Hammond -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of meredith lamb Sent: Wednesday, October 24, 2007 7:10 PM To: psn-l@.............. Subject: Re: Mystery item and its potential seismometry uses/s? Hi Jerry and all, =20 I put up some text and 3 more pictures of a rather unusual pendulum (horizontal sensing), on the web, and some very brief text relating to its other vertical sensing use/s. The pendulum is essentially a hanging mass or "S-G" type. The aluminum looks to be quite useful for a variety of seismometer = setups....without...as much material being used. Fun stuff! See: =20 http://home.earthlink.net/~meredithlamb/ =20 Take care, Meredith Lamb =20 On 10/24/07, Jerry Payton wrote:=20 OK, Meredith. I give up and curiosity has got this cat. It reminds me = of an oar-lock, but what was you idea? I've seen no replies to your = question and there seems to be a lull right now in EQ's. Let's stir up some discussion!=20 Regards, Jerry Payton =20 Message
Hi,=20 The design suggests to me that it may have been connected to a = round object=20 such as a sailboat's mast. I once read about a counter balance device = that=20 reduced the port/starboard sway when a boat is at anchor buy using a=20 counterbalance pendulum to create an apposing force that reduces the = wave=20 energy. The rollers in the top photo suggest to me that they would allow = the=20 base object to be hoisted to the upper portion of a mast = increasing=20 the effect of the pendulum. Here is a link to some = patents that=20 describe this idea. www.freepatent= sonline.com/CCL-114-122.html=20
 
 My guess, Steve Hammond
-----Original Message-----
From:=20 psn-l-request@.............. [mailto:psn-l-request@............... = On=20 Behalf Of meredith lamb
Sent: Wednesday, October 24, = 2007 7:10=20 PM
To: psn-l@..............
Subject: Re: Mystery = item and=20 its potential seismometry uses/s?

Hi Jerry and all,
 
I put up some text and 3 more pictures of a rather unusual = pendulum=20 (horizontal
sensing), on the web, and some very brief text relating to = its other=20 vertical sensing
use/s.  The pendulum is essentially a hanging mass or "S-G"=20 type.  The aluminum
looks to be quite useful for a variety of seismometer=20 setups....without...as much
material being used.  Fun stuff!  See:
 
http://home.earthlink.n= et/~meredithlamb/
 
Take care, Meredith Lamb

 
On 10/24/07, Jerry=20 Payton <gpayton880@.......>=20 wrote:=20
OK, Meredith.  I give up and curiosity has got = this=20 cat.  It reminds me of an oar-lock, but what was you = idea?  I've=20 seen no replies to your question and there seems to be a lull right = now in=20 EQ's.  Let's stir up some discussion!
Regards,
Jerry Payton
=
 
Subject: Re: Digest from 10/24/2007 00:00:50 From: Randall Peters PETERS_RD@.......... Date: Thu, 25 Oct 2007 08:59:01 -0400 It's a neat piece , Meredith; however, I see a serious problem with bearing friction when it comes to use in a seismometer. Rolling friction is really complex, as evidenced by the paper I wrote at http://arxiv.org/abs/physics/0506143 My expectation is that you will find challenges due to `stiction' since the decay of your system (independent of damping that you supply to the instrument by design) is more in the category of Coulomb friction than forms that result in exponential decay. As is well known for Coulomb friction, the static coefficient is greater than the kinetic coefficient. Consequently, you would probably need to provide some way to dither your instrument to have much in the way of sensitivity. Randall Peters psn-l-digest-request@.............. wrote: > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Mystery item and its potential seismometry uses/s? > From: "Jerry Payton" > Date: Wed, 24 Oct 2007 10:56:15 -0500 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0055_01C8162C.7F61FF40 > Content-Type: text/plain; > charset="Windows-1252" > Content-Transfer-Encoding: 7bit > > OK, Meredith. I give up and curiosity has got this cat. It reminds me of > an oar-lock, but what was you idea? I've seen no replies to your question > and there seems to be a lull right now in EQ's. Let's stir up some > discussion! > Regards, > Jerry Payton > > ----- Original Message ----- > From: meredith lamb > To: psn-l@.............. > Sent: Tuesday, October 09, 2007 8:28 PM > Subject: Mystery item and its potential seismometry uses/s? > > Hi all, > > I think it might be fun for those of you who are amateur or real > "engineers"; > to come up with their own thoughts and use/s for a couple pictures of a item > at: > > http://home.earthlink.net/~meredithlamb/ > > I have my own (surprising) and varied uses in mind; what's yours? > > Meredith Lamb > > ------=_NextPart_000_0055_01C8162C.7F61FF40 > Content-Type: text/html; > charset="Windows-1252" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Dwindows-1252"> > > > > >
OK, Meredith.  I give up and curiosity has got this = > cat. =20 > It reminds me of an oar-lock, but what was you idea?  I've seen no = > replies=20 > to your question and there seems to be a lull right now in EQ's.  = > Let's=20 > stir up some discussion!
>
Regards,
>
Jerry Payton
>
 
>
----- Original Message -----=20 >
From: title=3Dpaleoartifact@......... = > href=3D"mailto:paleoartifact@.........">meredith=20 > lamb
> >
Sent: Tuesday, October 09, 2007 8:28 PM
>
Subject: Mystery item and its potential seismometry=20 > uses/s?
>

>
Hi all,
>
 
>
I think it might be fun for those of you who are amateur or real=20 > "engineers";
>
to come up with their own thoughts and use/s for a couple pictures = > of a=20 > item at:
>
 
>
href=3D"http://home.earthlink.net/~meredithlamb/">http://home.earthlink.n= > et/~meredithlamb/
>
 
>
I have my own (surprising) and varied uses in mind; what's = > yours?
>
 
>
Meredith Lamb
>
 
>
 
> > ------=_NextPart_000_0055_01C8162C.7F61FF40-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 2 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Mystery item and its potential seismometry uses/s? > From: > Date: Wed, 24 Oct 2007 11:11:04 -0600 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_000C_01C8162E.914B0A60 > Content-Type: text/plain; > charset="Windows-1252" > Content-Transfer-Encoding: quoted-printable > > Jerry, You've got that right................This is my slowest month = > for a year, day after day very uninteresting screens. Maybe tomorrow? > Since I have no earthquakes to discuss...........Could this device be a = > support for a large dia. pipe? > > As a part of a Seismic device, here is my suggestion: > Get a large piece of white butcher paper 48" x 48" Draw a center point = > on the piece of paper, using a black #2 pencil, connecting two opposite = > diagonal corners. > Carefully position one corner of the paper facing true north and the = > opposite corner south. > Place this device in the center of the paper and align it's support = > shaft along the N/S axis. > Trace the profile of the entire device on to the paper using the black = > #2 pencil. > > Wait for a large earthquake, >7 M, closer than 100 miles. > After the large event, retrace the new position of the device's profile, = > using a red #2 Pencil. > Comparing the original position profile with the new position profile, = > one may be able to plot the general direction of the epicenter, and = > estimate the magnitude. Unless it move greater than 24" from center. > Thanks,=20 > Ted > > ----- Original Message -----=20 > From: Jerry Payton=20 > To: psn-l@................. > Sent: Wednesday, October 24, 2007 9:56 AM > Subject: Re: Mystery item and its potential seismometry uses/s? > > OK, Meredith. I give up and curiosity has got this cat. It reminds = > me of an oar-lock, but what was you idea? I've seen no replies to your = > question and there seems to be a lull right now in EQ's. Let's stir up = > some discussion! > Regards, > Jerry Payton > > ----- Original Message -----=20 > From: meredith lamb=20 > To: psn-l@................. > Sent: Tuesday, October 09, 2007 8:28 PM > Subject: Mystery item and its potential seismometry uses/s? > > Hi all, > > I think it might be fun for those of you who are amateur or real = > "engineers";=20 > to come up with their own thoughts and use/s for a couple pictures of = > a item at: > > http://home.earthlink.net/~meredithlamb/ > > I have my own (surprising) and varied uses in mind; what's yours? > > Meredith Lamb > > ------=_NextPart_000_000C_01C8162E.914B0A60 > Content-Type: text/html; > charset="Windows-1252" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Dwindows-1252"> > > > > >
Jerry,  You've got that=20 > right................This is my slowest month for a year, day after day = > very=20 > uninteresting screens.   Maybe tomorrow?
>
Since I have no earthquakes to=20 > discuss...........Could this device be a support for a large dia.=20 > pipe?
>
 
>
As a part of a Seismic device, here is = > my=20 > suggestion:
>
Get a large piece of white butcher = > paper 48" x 48"=20 > Draw a center point on the piece of paper, using a black #2 pencil, = > connecting=20 > two opposite diagonal corners.
>
Carefully position one corner of the = > paper facing=20 > true north and the opposite corner south.
>
Place this device in the center of the = > paper and=20 > align it's support shaft along the N/S axis.
>
Trace the profile of the entire device = > on to the=20 > paper using the black #2 pencil.
>
 
>
Wait for a large earthquake, >7 M, = > closer than=20 > 100 miles.
>
After the large event, retrace the new = > position of=20 > the device's profile, using a red #2 Pencil.
>
Comparing the original = > position profile with=20 > the new position profile, one may be able to plot the general = > direction of=20 > the epicenter, and estimate the magnitude.  Unless it move greater = > than 24"=20 > from center.
>
Thanks,
>
Ted
>
 
>
 
>
----- Original Message -----
>
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = > BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> > style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = > black">From:=20 > Jerry = > Payton=20 > > >
Sent: Wednesday, October 24, = > 2007 9:56=20 > AM
>
Subject: Re: Mystery item and = > its=20 > potential seismometry uses/s?
>

>
OK, Meredith.  I give up and curiosity has got this=20 > cat.  It reminds me of an oar-lock, but what was you idea?  = > I've=20 > seen no replies to your question and there seems to be a lull right = > now in=20 > EQ's.  Let's stir up some discussion!
>
Regards,
>
Jerry Payton
>
 
>
----- Original Message -----=20 >
From: title=3Dpaleoartifact@......... = > href=3D"mailto:paleoartifact@.........">meredith=20 > lamb
> >
Sent: Tuesday, October 09, 2007 8:28 PM
>
Subject: Mystery item and its potential seismometry=20 > uses/s?
>

>
Hi all,
>
 
>
I think it might be fun for those of you who are amateur or real=20 > "engineers";
>
to come up with their own thoughts and use/s for a couple = > pictures of a=20 > item at:
>
 
>
= > href=3D"http://home.earthlink.net/~meredithlamb/">http://home.earthlink.n= > et/~meredithlamb/
>
 
>
I have my own (surprising) and varied uses in mind; what's = > yours?
>
 
>
Meredith Lamb
>
 
>
 
> > ------=_NextPart_000_000C_01C8162E.914B0A60-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 3 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Mystery item and its potential seismometry uses/s? > From: "meredith lamb" > Date: Wed, 24 Oct 2007 20:09:43 -0600 > > ------=_Part_9710_24185849.1193278183386 > Content-Type: text/plain; charset=ISO-8859-1 > Content-Transfer-Encoding: 7bit > Content-Disposition: inline > > Hi Jerry and all, > > I put up some text and 3 more pictures of a rather unusual pendulum > (horizontal > sensing), on the web, and some very brief text relating to its other > vertical sensing > use/s. The pendulum is essentially a hanging mass or "S-G" type. The > aluminum > looks to be quite useful for a variety of seismometer setups....without...as > much > material being used. Fun stuff! See: > > http://home.earthlink.net/~meredithlamb/ > > Take care, Meredith Lamb > > On 10/24/07, Jerry Payton wrote: > > > > *OK, Meredith. I give up and curiosity has got this cat. It reminds me > > of an oar-lock, but what was you idea? I've seen no replies to your > > question and there seems to be a lull right now in EQ's. Let's stir up some > > discussion!* > > *Regards,* > > *Jerry Payton* > > ** > > > > ------=_Part_9710_24185849.1193278183386 > Content-Type: text/html; charset=ISO-8859-1 > Content-Transfer-Encoding: 7bit > Content-Disposition: inline > >
Hi Jerry and all,
>
 
>
I put up some text and 3 more pictures of a rather unusual pendulum (horizontal
>
sensing), on the web, and some very brief text relating to its other vertical sensing
>
use/s.  The pendulum is essentially a hanging mass or "S-G" type.  The aluminum
>
looks to be quite useful for a variety of seismometer setups....without...as much
>
material being used.  Fun stuff!  See:
>
 
> >
 
>
Take care, Meredith Lamb

 
>
On 10/24/07, Jerry Payton <gpayton880@.......> wrote: >
>
>
OK, Meredith.  I give up and curiosity has got this cat.  It reminds me of an oar-lock, but what was you idea?  I've seen no replies to your question and there seems to be a lull right now in EQ's.  Let's stir up some discussion! >
>
Regards,
>
Jerry Payton
>
 
> > ------=_Part_9710_24185849.1193278183386-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 4 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: RE: Mystery item and its potential seismometry uses/s? > From: "Steve Hammond" > Date: Wed, 24 Oct 2007 23:24:27 -0700 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0001_01C81695.060A0FC0 > Content-Type: text/plain; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > > Hi, The design suggests to me that it may have been connected to a round > object such as a sailboat's mast. I once read about a counter balance = > device > that reduced the port/starboard sway when a boat is at anchor buy using = > a > counterbalance pendulum to create an apposing force that reduces the = > wave > energy. The rollers in the top photo suggest to me that they would allow = > the > base object to be hoisted to the upper portion of a mast increasing the > effect of the pendulum. Here is a link to some patents that describe = > this > idea. www.freepatentsonline.com/CCL-114-122.html=20 > =20 > My guess, Steve Hammond > > -----Original Message----- > From: psn-l-request@.............. [mailto:psn-l-request@............... = > On > Behalf Of meredith lamb > Sent: Wednesday, October 24, 2007 7:10 PM > To: psn-l@.............. > Subject: Re: Mystery item and its potential seismometry uses/s? > > Hi Jerry and all, > =20 > I put up some text and 3 more pictures of a rather unusual pendulum > (horizontal > sensing), on the web, and some very brief text relating to its other > vertical sensing > use/s. The pendulum is essentially a hanging mass or "S-G" type. The > aluminum > looks to be quite useful for a variety of seismometer = > setups....without...as > much > material being used. Fun stuff! See: > =20 > http://home.earthlink.net/~meredithlamb/ > =20 > Take care, Meredith Lamb > > =20 > On 10/24/07, Jerry Payton wrote:=20 > > OK, Meredith. I give up and curiosity has got this cat. It reminds me = > of > an oar-lock, but what was you idea? I've seen no replies to your = > question > and there seems to be a lull right now in EQ's. Let's stir up some > discussion!=20 > Regards, > Jerry Payton > > =20 > > ------=_NextPart_000_0001_01C81695.060A0FC0 > Content-Type: text/html; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Dus-ascii"> > Message > > > >
size=3D2>Hi,=20 > The design suggests to me that it may have been connected to a = > round object=20 > such as a sailboat's mast. I once read about a counter balance device = > that=20 > reduced the port/starboard sway when a boat is at anchor buy using a=20 > counterbalance pendulum to create an apposing force that reduces the = > wave=20 > energy. The rollers in the top photo suggest to me that they would allow = > the=20 > base object to be hoisted to the upper portion of a mast = > increasing=20 > the effect of the pendulum. Here is a link to some = > patents that=20 > describe this idea.  href=3D"http://www.freepatentsonline.com/CCL-114-122.html">www.freepatent= > sonline.com/CCL-114-122.html=20 >
>
size=3D2> class=3Da> 
>
> size=3D2> My guess, Steve Hammond
>
>
>
align=3Dleft> face=3DTahoma size=3D2>-----Original Message-----
From:=20 > psn-l-request@.............. [mailto:psn-l-request@............... = > On=20 > Behalf Of meredith lamb
Sent: Wednesday, October 24, = > 2007 7:10=20 > PM
To: psn-l@..............
Subject: Re: Mystery = > item and=20 > its potential seismometry uses/s?

>
Hi Jerry and all,
>
 
>
I put up some text and 3 more pictures of a rather unusual = > pendulum=20 > (horizontal
>
sensing), on the web, and some very brief text relating to = > its other=20 > vertical sensing
>
use/s.  The pendulum is essentially a hanging mass or "S-G"=20 > type.  The aluminum
>
looks to be quite useful for a variety of seismometer=20 > setups....without...as much
>
material being used.  Fun stuff!  See:
>
 
>
= > href=3D"http://home.earthlink.net/~meredithlamb/">http://home.earthlink.n= > et/~meredithlamb/
>
 
>
Take care, Meredith Lamb

 
>
On 10/24/07, class=3Dgmail_sendername>Jerry=20 > Payton < href=3D"mailto:gpayton880@.......">gpayton880@.......>=20 > wrote:=20 >
style=3D"PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: = > #ccc 1px solid"> >
>
OK, Meredith.  I give up and curiosity has got = > this=20 > cat.  It reminds me of an oar-lock, but what was you = > idea?  I've=20 > seen no replies to your question and there seems to be a lull right = > now in=20 > EQ's.  Let's stir up some discussion!
>
Regards,
>
Jerry Payton
> = >
 
QUOTE> > > ------=_NextPart_000_0001_01C81695.060A0FC0-- > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-DIGEST-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. Subject: Peters study of complex friction From: John Lahr johnjan@........ Date: Thu, 25 Oct 2007 07:57:02 -0700 This is an interesting point that Randall makes. I suppose if there is always some movement due to microseisms, then the static friction will not come into play... but maybe not .... at the end of each swing it may be a factor anyway, causing the response to be nonlinear. I wonder if there are also complexities of this sort in other types of hinge that involve flexure of a material? John >Date: Thu, 25 Oct 2007 08:59:01 -0400 >From: Randall Peters >It's a neat piece , Meredith; however, I see a serious problem with >bearing friction when it comes to use in >a seismometer. Rolling friction is really complex, as evidenced by >the paper I wrote at >http://arxiv.org/abs/physics/0506143 > My expectation is that you will find challenges due to `stiction' > since the decay of your system (independent >of damping that you supply to the instrument by design) is more in >the category of Coulomb friction than >forms that result in exponential decay. As is well known for >Coulomb friction, the static coefficient is greater than the kinetic >coefficient. Consequently, you would probably need to provide some >way to dither your instrument to have much in the way of sensitivity. > >Randall Peters __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Thu, 25 Oct 2007 11:52:49 -0600 Hi Steve and all, I don't really know what the item was originally used for. The "wear" pattern only suggests a horizontal load use for this particular item. There is indeed likely a wide variety of use variations as you web referenced. Meanwhile...I've added another 6th picture and text for a crude "crossed rod" pivot using the same item. The "crossed rod" type of pivot is in my opinion much better than using ball bearings, as from past table top edge experiments; its resulting visual low level small movement response (less than 1/16") seems to be quite abit more responsive....i.e., its undampened visual movement has been known to continue for ~ 2 hours more than using a variety of ball bearings. In this picture however, it is different as the 90 degree rods serve to limit unitentional assembly displacement in the lateral axis...which is a improvement over a simple straight rod riding atop the two extended table top rods. http://home.earthlink.net/~meredithlamb/ On 10/25/07, Steve Hammond wrote: > > Hi, The design suggests to me that it may have been connected to a round > object such as a sailboat's mast. I once read about a counter balance device > that reduced the port/starboard sway when a boat is at anchor buy using a > counterbalance pendulum to create an apposing force that reduces the wave > energy. The rollers in the top photo suggest to me that they would allow the > base object to be hoisted to the upper portion of a mast increasing the > effect of the pendulum. Here is a link to some patents that describe this > idea. www.freepatentsonline.com/CCL-114-122.html > > My guess, Steve Hammond > >
Hi Steve and all,
 
I don't really know what the item was originally used for.  The "wear" pattern
only suggests a horizontal load use for this particular item.  There is indeed likely a
wide variety of use variations as you web referenced.
 
Meanwhile...I've added another 6th picture and text for a crude "crossed rod" pivot using
the same item.  The "crossed rod" type of pivot is in my opinion much better
than using ball bearings, as from past table top edge experiments; its resulting visual
low level small movement response (less than 1/16") seems to be quite abit more responsive....i.e.,
its undampened visual movement has been known to continue for ~ 2 hours more than
using a variety of ball bearings.  In this picture however, it is different as the 90 degree rods serve
to limit unitentional assembly displacement in the lateral axis...which is a improvement over
a simple straight rod riding atop the two extended table top rods.   
 
 
 


 
On 10/25/07, Steve Hammond <shammon1@............. > wrote:
Hi, The design suggests to me that it may have been connected to a round object such as a sailboat's mast. I once read about a counter balance device that reduced the port/starboard sway when a boat is at anchor buy using a counterbalance pendulum to create an apposing force that reduces the wave energy. The rollers in the top photo suggest to me that they would allow the base object to be hoisted to the upper portion of a mast increasing the effect of the pendulum. Here is a link to some patents that describe this idea.  www.freepatentsonline.com/CCL-114-122.html
 
 My guess, Steve Hammond
Subject: Re: Digest from 10/24/2007 00:00:50 From: "meredith lamb" paleoartifact@......... Date: Thu, 25 Oct 2007 12:13:35 -0600 Hi Randall, Thanks for the email and notes. I agree that ball bearings aren't a very good pivot point as I've seen a comparison of ball bearings to a "crossed rod" pivot; i.e., the low level mass pivot response of the ball bearings was outright "locked" compared to the crossed rod pivot where mass movement is less than 1/16"....right in the neighborhood range where most seismic response occurs. I won't pretend to grasp totally all you've wrote of. I do appreciate your contributions! Take care, Meredith Lamb On 10/25/07, Randall Peters wrote: > > It's a neat piece , Meredith; however, I see a serious problem with > bearing friction when it comes to use in > a seismometer. Rolling friction is really complex, as evidenced by the > paper I wrote at > http://arxiv.org/abs/physics/0506143 > My expectation is that you will find challenges due to `stiction' since > the decay of your system (independent > of damping that you supply to the instrument by design) is more in the > category of Coulomb friction than > forms that result in exponential decay. As is well known for Coulomb > friction, the static coefficient is greater than the kinetic > coefficient. Consequently, you would probably need to provide some way to > dither your instrument to have much in the way of sensitivity. > > Randall Peters > > >
Hi Randall,
 
Thanks for the email and notes.  I agree that ball bearings aren't a very good pivot point as I've seen
a comparison of ball bearings to a "crossed rod" pivot; i.e., the low level mass pivot response of the ball
bearings was outright "locked" compared to the crossed rod pivot where mass movement is less than
1/16"....right in the neighborhood range where most seismic response occurs.
 
I won't pretend to grasp totally all you've wrote of.  I do appreciate your contributions!
 
Take care, Meredith Lamb    

 
On 10/25/07, Randall Peters <PETERS_RD@..........> wrote:
It's a neat piece , Meredith; however, I see a serious problem with bearing friction when it comes to use in
a seismometer.  Rolling friction is really complex, as evidenced by the paper I wrote at
http://arxiv.org/abs/physics/0506143
My expectation is that you will find challenges due to `stiction' since the decay of your system (independent
of damping that you supply to the instrument by design) is more in the category of Coulomb friction than
forms that result in exponential decay.  As is well known for Coulomb friction, the static coefficient is greater than the kinetic coefficient.  Consequently, you would probably need to provide some way to dither your instrument to have much in the way of sensitivity.

Randall Peters


Subject: Re: Mystery item and its potential seismometry uses/s? From: John Lahr johnjan@........ Date: Thu, 25 Oct 2007 13:07:55 -0700 At 10:52 AM 10/25/2007, you wrote: >...I've added another 6th picture and text for a crude "crossed rod" >pivot using >the same item. Meredith, It would be interesting to test this arrangement of rods. I think that due to the angles, the pivot point will need to rub rather than roll. If that's the case there will be much greater friction. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mystery item and its potential seismometry uses/s? From: "Geoff" gmvoeth@........... Date: Thu, 25 Oct 2007 13:37:27 -0700 Interesting, I would think if you get a natural damping from frictional forces of possibly 1.4 ( Q = 0.7) you would not need any magnetic or other damping ? ----- Original Message ----- From: "John Lahr" To: Sent: Thursday, October 25, 2007 1:07 PM Subject: Re: Mystery item and its potential seismometry uses/s? > At 10:52 AM 10/25/2007, you wrote: >>...I've added another 6th picture and text for a crude "crossed rod" >>pivot using >>the same item. > > Meredith, > > It would be interesting to test this arrangement of rods. I think > that due to the angles, > the pivot point will need to rub rather than roll. If that's the > case there will be much > greater friction. > > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Peters study of complex friction From: ChrisAtUpw@....... Date: Thu, 25 Oct 2007 16:53:08 EDT In a message dated 25/10/2007, johnjan@........ writes: This is an interesting point that Randall makes. I suppose if there is always some movement due to microseisms, then the static friction will not come into play... but maybe not .... at the end of each swing it may be a factor anyway, causing the response to be nonlinear. Hi All, If you have simple rolling of a hard cylinder / sphere on another hard surface, no direct friction will be involved, although a small loss will occur as the rolling surfaces are elastically compressed. If you have any sliding, the movement will alternate from one stick / slip situation to another in small jerky steps. I wonder if there are also complexities of this sort in other types of hinge that involve flexure of a material? In the V suspension shown, vibrations will tend to flex the rods and will probably markedly increase the loss in the suspension due to sliding friction. _http://home.earthlink.net/~meredithlamb/id1.html_ (http://home.earthlink.net/~meredithlamb/id1.html) Regards, Chris Chapman
In a message dated 25/10/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>This is=20 an interesting point that Randall makes.  I suppose if there
is=20 always some movement due to microseisms, then the static friction
will= not=20 come into play...  but maybe not .... at the end of each
swing it= may=20 be a factor anyway, causing the response to be nonlinear.
Hi All,
 
    If you have simple rolling of a hard cylinder /= =20 sphere on another hard surface, no direct friction will be involved, althoug= h a=20 small loss will occur as the rolling surfaces are elastically compressed. If= you=20 have any sliding, the movement will alternate from one stick / sli= p=20 situation to another in small jerky steps. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I wonder=20 if there are also complexities of this sort in other types of hinge that=20 involve flexure of a material?
    In the V suspension shown, vibrations will tend= to=20 flex the rods and will probably markedly increase the loss in the suspension= due=20 to sliding friction. http://home.earthl= ink.net/~meredithlamb/id1.html
 
    Regards,
 
    Chris Chapman
Subject: Re: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Thu, 25 Oct 2007 16:24:23 -0600 Hi John, Yes.... you are correct...the rod would twist sideways (rub), rather than roll as a crossed rod pivot should. All is not lost however with the aluminum; it does have another pair of holes that can accomodate a rod through it. Yes....(ha), I also put up yet another photo (bottom of the web page) of a more correct crossed rod pivot and denoted my error. http://home.earthlink.net/~meredithlamb/ Meredith On 10/25/07, John Lahr wrote: > > At 10:52 AM 10/25/2007, you wrote: > >...I've added another 6th picture and text for a crude "crossed rod" > >pivot using > >the same item. > > Meredith, > > It would be interesting to test this arrangement of rods. I think > that due to the angles, > the pivot point will need to rub rather than roll. If that's the > case there will be much > greater friction. > > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >
Hi John,
 
Yes.... you are correct...the rod would twist sideways (rub), rather than roll
as a crossed rod pivot should. 
 
All is not lost however with the aluminum; it does have another pair of holes
that can accomodate a rod through it.
 
Yes....(ha), I also put up yet another photo (bottom of the web page) of a more
correct crossed rod pivot and denoted my error.
 

Meredith
 
On 10/25/07, John Lahr <johnjan@........> wrote:
At 10:52 AM 10/25/2007, you wrote:
>...I've added another 6th picture and text for a crude "crossed rod"
>pivot using
>the same item.

Meredith,

It would be interesting to test this arrangement of rods.  I think
that due to the angles,
the pivot point will need to rub rather than roll.  If that's the
case there will be much
greater friction.

John


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
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Subject: Question regarding two seismometers From: "Kay Wyatt" kwyatt@............. Date: Fri, 26 Oct 2007 11:01:48 -0700 Greetings fellow PSN enthusiasts, My name is Kay Wyatt and I am the Director of the Oregon Shakes Program = (www.OregonShakes.com) which is trying to put seismograph in all public = schools in Oregon starting in Lincoln County. We have funding to = purchase three AS-1 seismographs, but I am looking at alternatives = before we make the purchase. I currently run an AS-1 at my house and = maintain an AS-1 at our local after school enrichment program in Depoe = Bay Oregon. Does anybody have the VolksMeter II which is made by RLL Instruments, a = division of Zoltech Corp. Their website is at = http://www.rllinstruments.com/. If anybody has any experience with this = system (good or bad) I would be most interested in hearing from you. I was also looking at the SEP Seismometer System which is sold by MUTR = in the UK. Their website is at = http://www.mutr.co.uk/catalog/product_info.php?cPath=3D18_412&products_id= =3D9047. Again, if anybody has any experience with this, good or bad, I = am most interested. Also, if you have suggestions on other educational seismometers, I would = be very interested. Our Lincoln County kids are incredibly excited = about this program. We may have a few budding PSN'rs. Perhaps a PSN = Junior listserver might be in order ;-) Thanks, Kay Wyatt
Greetings fellow PSN enthusiasts,
 
My name is Kay Wyatt and I am the Director of = the Oregon=20 Shakes Program (www.OregonShakes.com)=20 which is trying to put seismograph in all public schools in Oregon = starting in=20 Lincoln County.  We have funding to purchase three AS-1 = seismographs, but I=20 am looking at alternatives before we make the purchase.  I = currently run an=20 AS-1 at my house and maintain an AS-1 at our local after school = enrichment=20 program in Depoe Bay Oregon.
 
Does anybody have the VolksMeter II which is = made by RLL=20 Instruments, a division of Zoltech Corp.  Their website is at http://www.rllinstruments.com/. =20 If anybody has any experience with this system (good or bad) I would be = most=20 interested in hearing from you.
 
I was also looking at the SEP Seismometer System = which is=20 sold by MUTR in the UK.  Their website is at http://www.mutr.co.uk/catalog/product_info.php?cPath= =3D18_412&products_id=3D9047. =20 Again, if anybody has any experience with this, good or bad, I am most=20 interested.
 
Also, if you have suggestions on other = educational=20 seismometers, I would be very interested.  Our Lincoln County kids = are=20 incredibly excited about this program.  We may have a few budding=20 PSN'rs.  Perhaps a PSN Junior listserver might be in=20 order    ;-)
 
Thanks,
Kay Wyatt
 
Subject: A rough trial HD pivot vertical From: "meredith lamb" paleoartifact@......... Date: Sat, 27 Oct 2007 13:03:58 -0600 Hi all, Just for fun, I put a web site with pictures of a rough trial vertical using hard drive hole inner surface disks with a 1/4" rod as the pivot. The "base" layout is roughly similar to that of the Georgia Tech vertical; which does not use a mast. The perforated steel tubing (Ace Hardware) helped make it easy to construct. I have not extensively "played" with it, so the period is only a fraction over 1 second. Perhaps....the main points of it all, are the HD disks and the rolling rod as the pivot; and the extreme ease of assembly with the Ace Hardware perforated steel tubing, that served as the "base plate", that was utilized. http://home.earthlink.net/~meredithlamb/hdpivotvertical/ Take care, Meredith Lamb
Hi all,
 
Just for fun, I put a web site with pictures of a rough trial vertical using hard drive
hole inner surface disks with a 1/4" rod as the pivot.  The "base" layout is roughly
similar to that of the Georgia Tech vertical; which does not use a mast.  The
perforated steel tubing (Ace Hardware) helped make it easy to construct.  I have
not extensively "played" with it, so the period is only a fraction over 1 second.
 
Perhaps....the main points of it all, are the HD disks and the rolling rod as the
pivot; and the extreme ease of assembly with the Ace Hardware perforated steel
tubing, that served as the "base plate", that was utilized.
 
 
 
Take care, Meredith Lamb
 
  
Subject: Different types of Pendulums From: tchannel1@............ Date: Sat, 27 Oct 2007 15:23:56 -0600 Hi Folks, Sometime in the past I saw a web site describing different = type of pendulums used in sensors. I don't remember their names, but 1. one was a long vertical rod, with a center pivot, it contained a = mass at the top of the rod and a mass at the bottom of the rod. 2. Another pendulum was a horz rod which had a short vertical rod = pointing up from the center of the long horz rod. The pivot point was = at the top of this short vertical. There may have been two or so more pendulum illustrated. My question has to do with 1. I thought this pendulum (positioned like = an airplane propeller) was able to adjust it's period by moving the top = and or bottom mass, up or down the rod? I made a simply mock up of this illustration, but was not successful in = any way as the mock up was too crude. To me it was similar to the = folded pendulum, as it had a normal and inverted pendulum, one apposing = the other? Can one adjust this arrangement to result in an extended period???????? = Does anyone know of this wed site or one similar? Thanks, Ted
Hi Folks, Sometime in the past I saw a = web site=20 describing different type of pendulums used in sensors.  I don't = remember=20 their names, but
 
1.  one was a long vertical = rod, with a=20 center pivot, it contained a mass at the top of the rod and a mass at = the bottom=20 of the rod.
 
 
2. Another pendulum was a horz rod = which had a=20 short vertical rod pointing up from the center of the long horz = rod.  The=20 pivot point was at the top of this short vertical.
 
There may have been two or so more = pendulum=20 illustrated.
 
My question has to do with 1.  I = thought this=20 pendulum (positioned like an airplane propeller) was able to adjust it's = period=20 by moving the top and or bottom mass, up or down the rod?
I made a simply mock up of this = illustration, but=20 was not successful in any way as the mock up was too crude.  To me = it was=20 similar to the folded pendulum, as it had a normal and inverted = pendulum, one=20 apposing the other?
Can one adjust this arrangement to = result in an=20 extended period????????   Does anyone know of this wed site or = one=20 similar?
 
Thanks, Ted
Subject: Re: Different types of Pendulums From: ChrisAtUpw@....... Date: Sat, 27 Oct 2007 17:44:22 EDT In a message dated 27/10/2007 22:23:56 GMT Daylight Time, tchannel1@............ writes: Hi Folks, Sometime in the past I saw a web site describing different types of pendulums used in sensors. I don't remember their names, but 1. one was a long vertical rod, with a center pivot, it contained a mass at the top of the rod and a mass at the bottom of the rod. My question has to do with 1. I thought this pendulum (positioned like an airplane propeller) was able to adjust it's period by moving the top and or bottom mass, up or down the rod? I made a simply mock up of this illustration, but was not successful in any way. Can one adjust this arrangement to result in an extended period? Does anyone know of this web site or one similar? Hi Ted, There are several possible systems, but you need to suspend the pendulum near the middle, a small height above the centre of gravity. This gives a high moment of inertia due to the masses at the ends and the small restoring force due to 2x mass operating just below the suspension axis. It should work fine. You can also vary the position of one of the masses. Regards, Chris Chapman
In a message dated 27/10/2007 22:23:56 GMT Daylight Time,=20 tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Folks, Sometime in the past I saw a we= b site=20 describing different types of pendulums used in sensors.  I don't=20 remember their names, but
 
1.  one was a long vertical rod= , with a=20 center pivot, it contained a mass at the top of the rod and a mass at the=20 bottom of the rod.
 
My question has to do with 1.  I tho= ught=20 this pendulum (positioned like an airplane propeller) was able to adjust i= t's=20 period by moving the top and or bottom mass, up or down the rod?
I made a simply mock up of this illustrat= ion, but=20 was not successful in any way. Can one=20= adjust=20 this arrangement to result in an extended period? Does anyone know of this= web=20 site or one similar?
Hi Ted,
 
    There are several possible systems, but you nee= d to=20 suspend the pendulum near the middle, a small height above the centre=20 of gravity. This gives a high moment of inertia due to the masses=20= at=20 the ends and the small restoring force due to 2x mass operating just below t= he=20 suspension axis. It should work fine. You can also vary the position of= one=20 of the masses.
 
    Regards,
 
    Chris Chapman
Subject: Re: Different types of Pendulums From: John Lahr johnjan@........ Date: Sat, 27 Oct 2007 15:04:59 -0700 The "airplane-type" design is basically a "solid pendulum." Although the period can be made very long, the sensitivity becomes correspondingly low. I don't recommend this design. Cheers, John At 02:44 PM 10/27/2007, you wrote: >In a message dated 27/10/2007 22:23:56 GMT Daylight Time, >tchannel1@............ writes: >Hi Folks, Sometime in the past I saw a web site describing different >types of pendulums used in sensors. I don't remember their names, but > >1. one was a long vertical rod, with a center pivot, it contained a >mass at the top of the rod and a mass at the bottom of the rod. > >My question has to do with 1. I thought this pendulum (positioned >like an airplane propeller) was able to adjust it's period by moving >the top and or bottom mass, up or down the rod? >I made a simply mock up of this illustration, but was not successful >in any way. Can one adjust this arrangement to result in an extended >period? Does anyone know of this web site or one similar? > >Hi Ted, > > There are several possible systems, but you need to suspend the > pendulum near the middle, a small height above the centre of > gravity. This gives a high moment of inertia due to the masses at > the ends and the small restoring force due to 2x mass operating > just below the suspension axis. It should work fine. You can also > vary the position of one of the masses. > > Regards, > > Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Different types of Pendulums From: tchannel1@............ Date: Sat, 27 Oct 2007 16:58:42 -0600 Hi Chris, What you described below, I think, was one of the = illustration, Let me describe it this way........... Lets say a 36" horz rod.............from the balance point 18" connect a = short 2" x 4" (L) shape rod, the 2" leg is welded to the balance point = of the horz rod. Now the 4" leg is inserted into some sort of bearing, and the whole = thing swings back and forth from this 4" axle. You have two equal = masses, one on the left and one on the right of the 36" horz. rod. NOW = CAN one extend the period of the device by relocating one or other of = the masses? Thanks, Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Saturday, October 27, 2007 3:44 PM Subject: Re: Different types of Pendulums In a message dated 27/10/2007 22:23:56 GMT Daylight Time, = tchannel1@............ writes: Hi Folks, Sometime in the past I saw a web site describing different = types of pendulums used in sensors. I don't remember their names, but 1. one was a long vertical rod, with a center pivot, it contained a = mass at the top of the rod and a mass at the bottom of the rod. My question has to do with 1. I thought this pendulum (positioned = like an airplane propeller) was able to adjust it's period by moving the = top and or bottom mass, up or down the rod? I made a simply mock up of this illustration, but was not successful = in any way. Can one adjust this arrangement to result in an extended = period? Does anyone know of this web site or one similar? Hi Ted, There are several possible systems, but you need to suspend the = pendulum near the middle, a small height above the centre of gravity. = This gives a high moment of inertia due to the masses at the ends and = the small restoring force due to 2x mass operating just below the = suspension axis. It should work fine. You can also vary the position of = one of the masses.=20 Regards, Chris Chapman
Hi Chris,  What you described below, I think, was one of the=20 illustration,  Let me describe it this way...........
Lets say a 36" horz rod.............from the balance point 18" = connect a=20 short 2" x 4"  (L) shape rod, the 2" leg is welded to the balance = point of=20 the horz rod.
Now the 4" leg is inserted into some sort of bearing, and the whole = thing=20 swings back and forth from this 4" axle.   You have two equal = masses,=20 one on the left and one on the right of the 36" horz. rod.   = NOW=20 CAN  one extend the period of the device by relocating one or other = of the=20 masses?
 
Thanks, Ted
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Saturday, October 27, = 2007 3:44=20 PM
Subject: Re: Different types of = Pendulums

In a message dated 27/10/2007 22:23:56 GMT Daylight Time, tchannel1@............ = writes:
Hi Folks, Sometime in the past I = saw a web site=20 describing different types of pendulums used in sensors.  I = don't=20 remember their names, but
 
1.  one was a long = vertical rod, with=20 a center pivot, it contained a mass at the top of the rod and a mass = at the=20 bottom of the rod.
 
My question has to do with 1.  = I thought=20 this pendulum (positioned like an airplane propeller) was able to = adjust=20 it's period by moving the top and or bottom mass, up or down the=20 rod?
I made a simply mock up of this = illustration,=20 but was not successful in any way. Can one=20 adjust this arrangement to result in an extended period? Does anyone = know of=20 this web site or one similar?
Hi Ted,
 
    There are several possible systems, but = you need=20 to suspend the pendulum near the middle, a small height above the = centre=20 of gravity. This gives a high moment of inertia due to the = masses at=20 the ends and the small restoring force due to 2x mass operating just = below the=20 suspension axis. It should work fine. You can also vary the = position of=20 one of the masses.
 
    Regards,
 
    Chris=20 Chapman
Subject: Re: Different types of Pendulums From: tchannel1@............ Date: Sat, 27 Oct 2007 17:20:04 -0600 Hi Folks, I found the wed site again. http://www.phy.mtu.edu/~suits/PH3110/pendulums.html The two I mentioned are called "Balanced-Like" and "Nearly Balanced" Just wondering if anyone has worked with them. As I said I made a mock up, with no luck. But maybe my mock up was not done correctly. Ted ----- Original Message ----- From: "John Lahr" To: Sent: Saturday, October 27, 2007 4:04 PM Subject: Re: Different types of Pendulums > The "airplane-type" design is basically a "solid pendulum." Although the > period can be made > very long, the sensitivity becomes correspondingly low. I don't recommend > this design. > > Cheers, > John > > At 02:44 PM 10/27/2007, you wrote: >>In a message dated 27/10/2007 22:23:56 GMT Daylight Time, >>tchannel1@............ writes: >>Hi Folks, Sometime in the past I saw a web site describing different types >>of pendulums used in sensors. I don't remember their names, but >> >>1. one was a long vertical rod, with a center pivot, it contained a mass >>at the top of the rod and a mass at the bottom of the rod. >> >>My question has to do with 1. I thought this pendulum (positioned like an >>airplane propeller) was able to adjust it's period by moving the top and >>or bottom mass, up or down the rod? >>I made a simply mock up of this illustration, but was not successful in >>any way. Can one adjust this arrangement to result in an extended period? >>Does anyone know of this web site or one similar? >> >>Hi Ted, >> >> There are several possible systems, but you need to suspend the >> pendulum near the middle, a small height above the centre of gravity. >> This gives a high moment of inertia due to the masses at the ends and the >> small restoring force due to 2x mass operating just below the suspension >> axis. It should work fine. You can also vary the position of one of the >> masses. >> >> Regards, >> >> Chris Chapman > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Different types of Pendulums From: ChrisAtUpw@....... Date: Sat, 27 Oct 2007 20:38:04 EDT In a message dated 27/10/2007, tchannel1@............ writes: Hi Chris, What you described below, I think, was one of the illustration, Let me describe it this way........... Lets say a 36" horz rod.............from the balance point 18" connect a short 2" x 4" (L) shape rod, the 2" leg is welded to the balance point of the horz rod. Now the 4" leg is inserted into some sort of bearing, and the whole thing swings back and forth from this 4" axle. You have two equal masses, one on the left and one on the right of the 36" horz. rod. NOW CAN one extend the period of the device by relocating one or other of the masses? Hi Ted, You would need to move both masses equally, or they would not balace. If the rod is of low weight and the masses are K from the centre, the moment of inertia is roughly 2MK^2. The restoring force is roughly 2Mg x 4" x dTheta. Changes in the length of the 4" rod will make a big contribution to the period. As John has mentioned, the sensitivity to seismic motion is low, but if you use a quad NdFeB magnet + coil sensor, you can get 10x the output of a U Alnico magnet design. If you also design your amplifier for low noise, you can get maybe 1/10 the noise of available amplifiers. Referring to _http://jclahr.com/science/psn/cochrane/index.html_ (http://jclahr.com/science/psn/cochrane/index.html) if you reduce R29 from 400 K to 12 K and R10 from 5.1 K to 150 Ohm you will reduce the shot noise by ~x5 and also reduce the 1/f current noise. Using discreet low noise input transistors can give a further noise reduction of x5, or more. Using such a system as part of a chopper amplifier will dramatically reduce the 1/f voltage and current noise. See _http://www.linear.com.cn/pc/downloadDocument.do?navId=H0,C1,C1010,C1203,P1248,D4136_ (http://www.linear.com.cn/pc/downloadDocument.do?navId=H0,C1,C1010,C1203,P1248,D4136) I like the reference _http://www.phy.mtu.edu/~suits/PH3110/pendulums.html_ (http://www.phy.mtu.edu/~suits/PH3110/pendulums.html) The wide angle crossed wire suspension system is very interesting. But crossed foils might be more robust. You can also extend the period of Lehman and vertical pendulums up to x10 by magnetic repulsion. This modifies the force / position relationship, but you may then be very sensitive to local magnetic field noise. Regards, Chris Chapman
In a message dated 27/10/2007, tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Chris,  What you described below, I think, was one of the=20 illustration,  Let me describe it this way...........
Lets say a 36" horz rod.............from the balance point 18" connec= t a=20 short 2" x 4"  (L) shape rod, the 2" leg is welded to the balance poi= nt=20 of the horz rod.
Now the 4" leg is inserted into some sort of bearing, and the whole t= hing=20 swings back and forth from this 4" axle.   You have two equal=20 masses, one on the left and one on the right of the 36" horz. rod. &n= bsp;=20 NOW CAN  one extend the period of the device by relocating one or oth= er=20 of the masses?
Hi Ted,
 
    You would need to move both masses equally, or=20= they=20 would not balace. If the rod is of low weight and the masses are K from the=20 centre, the moment of inertia is roughly 2MK^2. The restoring force is rough= ly=20 2Mg x 4" x dTheta. Changes in the length of the 4" rod will make a big=20 contribution to the period.
 
    As John has mentioned, the sensitivity to seism= ic=20 motion is low, but if you use a quad NdFeB magnet + coil sensor, you can get= 10x=20 the output of a U Alnico magnet design. If you also design your amplifier fo= r=20 low noise, you can get maybe 1/10 the noise of available amplifiers.
    Referring to http://jclahr.com= /science/psn/cochrane/index.html if=20 you reduce R29 from 400 K to 12 K and R10 from 5.1 K to 150 Ohm you will red= uce=20 the shot noise by ~x5 and also reduce the 1/f current noise. Using= =20 discreet low noise input transistors can give a further noise reduction of x= 5,=20 or more. Using such a system as part of a chopper amplifier will dramaticall= y=20 reduce the 1/f voltage and current noise. See http://www.linear.com.cn/pc/downloadDocument.do?navId=3DH= 0,C1,C1010,C1203,P1248,D4136
 
    I like the reference http://www.phy.= mtu.edu/~suits/PH3110/pendulums.html The=20 wide angle crossed wire suspension system is very interesting. But crossed f= oils=20 might be more robust. You can also extend the period of Lehman and vertical=20 pendulums up to x10 by magnetic repulsion. This modifies the force /=20 position relationship, but you may then be very sensitive to local magnetic=20 field noise.
 
    Regards,
 
    Chris Chapman
Subject: Re: Different types of Pendulums From: "Geoff" gmvoeth@........... Date: Sat, 27 Oct 2007 17:40:37 -0700 Hello All; This Is All quite Interesting but no one seems to concentrate on the real devil your fighting which is gravity. In order to lengthen the period of a pendulum you must find some way of lowering the pull of gravity which is 32.17fpss that means you need to effectively reduce it to like 3.217fpss if you want a decent period. At least that is how I understand it. All these fancy things we do are essentially to reduce gravitational effects on the mass. You might use bouyancy to help you if you can find a fluid with high specific gravity like 5g/cm3 or more then use a small spring to do the rest on the mass. Whatever you can get to oppose gravity is in the game. If only someone could find a cheap way to oppose gravity ?? Light ( EM ) waves are themselves like a pendulum in that they oscillate seemingly between the potential ( E ) and the Kenetic ( B ) and who is to say there is nothing to dampen an EM wave since we simply can not ride with one till it dies out ??? Just a thought stimulated by this thread. Regards; geoff ----- Original Message ----- From: To: Sent: Saturday, October 27, 2007 4:20 PM Subject: Re: Different types of Pendulums > Hi Folks, I found the wed site again. > http://www.phy.mtu.edu/~suits/PH3110/pendulums.html The two I mentioned are > called "Balanced-Like" and "Nearly Balanced" > Just wondering if anyone has worked with them. As I said I made a mock up, > with no luck. But maybe my mock up was not done correctly. > Ted > > > > > > > ----- Original Message ----- > From: "John Lahr" > To: > Sent: Saturday, October 27, 2007 4:04 PM > Subject: Re: Different types of Pendulums > > >> The "airplane-type" design is basically a "solid pendulum." Although the >> period can be made >> very long, the sensitivity becomes correspondingly low. I don't recommend >> this design. >> >> Cheers, >> John >> >> At 02:44 PM 10/27/2007, you wrote: >>>In a message dated 27/10/2007 22:23:56 GMT Daylight Time, >>>tchannel1@............ writes: >>>Hi Folks, Sometime in the past I saw a web site describing different types >>>of pendulums used in sensors. I don't remember their names, but >>> >>>1. one was a long vertical rod, with a center pivot, it contained a mass >>>at the top of the rod and a mass at the bottom of the rod. >>> >>>My question has to do with 1. I thought this pendulum (positioned like an >>>airplane propeller) was able to adjust it's period by moving the top and >>>or bottom mass, up or down the rod? >>>I made a simply mock up of this illustration, but was not successful in >>>any way. Can one adjust this arrangement to result in an extended period? >>>Does anyone know of this web site or one similar? >>> >>>Hi Ted, >>> >>> There are several possible systems, but you need to suspend the >>> pendulum near the middle, a small height above the centre of gravity. >>> This gives a high moment of inertia due to the masses at the ends and the >>> small restoring force due to 2x mass operating just below the suspension >>> axis. It should work fine. You can also vary the position of one of the >>> masses. >>> >>> Regards, >>> >>> Chris Chapman >> >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of the >> message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: VolksMeter II From: "Jerry Payton" gpayton880@....... Date: Tue, 30 Oct 2007 08:28:17 -0500 After reading Kay Wyatt's email on the 26th, I have been looking at the VolkMeter II. It is something else, but the price = OUCH. I printed out their manual and am reading it now. I believe that it will be educational, especially about the WinSDR and WinQuake software settings. I am a real fuddy-duddy about HELP files. I don't like it when one just tell me, "This is the gas pedal", and stops at that. I want it to tell me that when I press it, you will go, and when you press harder you go faster! I like for help files to explain WHAT THEY DO, not simply what they are named. Off my soapbox now. I liked what Mrs. Wyatt was trying to do, similar to what you are doing, but larger scale, I think. I wanted remind you that I bought those fifty used tungsten drill bits. I have a lot left, if you should want to try the cross-roller method. Let me know and I send you what you need. I am not progressing very fast on my building. First, I am no much of a "tinkerer" and have to get my lazy bones out in the garage to work on it. Second, I keep changing my mind about the configuration of things. Chris had suggested, before he stopped helping, that I use a 3/4" x 6" cross bar, and connect two wire suspension cables. I tried that, but didn't like it. So, I am going back to something like John Cole used for suspension of the arm. I've got a little challenge in vertical alignment of the two pivot points too. I'm experimenting with that too. Annnnnnnnnd, it is getting cooler out in the garage. I broke down and bought an inexpensive drill press from Harbor Freight. It sure is handy. I've always wanted one for those special times that you need one. Regards, Jerry
After reading Kay Wyatt's email on the 26th, I have been looking at = the=20 VolkMeter II.  It is something else, but the price =3D OUCH.
 
I printed out their manual and am reading it now.  I believe = that it=20 will be educational, especially about the WinSDR and WinQuake software=20 settings.  I am a real fuddy-duddy about HELP files.  I don't = like it=20 when one just tell me, "This is the gas pedal", and stops at that.  = I want=20 it to tell me that when I press it, you will go, and when you press = harder you=20 go faster!  I like for help files to explain WHAT THEY DO, not = simply what=20 they are named.
 
Off my soapbox now.  I liked what Mrs. Wyatt was trying to do, = similar=20 to what you are doing, but larger scale, I think. 
 
I wanted remind you that I bought those fifty used tungsten drill=20 bits.  I have a lot left, if you should want to try the = cross-roller=20 method.  Let me know and I send you what you need.
 
I am not progressing very fast on my building.  First, I am no = much of=20 a "tinkerer" and have to get my lazy bones out in the garage to work on=20 it.  Second, I keep changing my mind about the configuration of=20 things.  Chris had suggested, before he stopped helping, that I use = a 3/4"=20 x 6" cross bar, and connect two wire suspension cables.  I tried = that, but=20 didn't like it.  So, I am going back to something like John Cole = used for=20 suspension of the arm. 
 
I've got a little challenge in vertical alignment of the two pivot = points=20 too.  I'm experimenting with that too.
 
Annnnnnnnnd, it is getting cooler out in the garage.  I broke = down and=20 bought an inexpensive drill press from Harbor Freight.  It sure is=20 handy.  I've always wanted one for those special times that you = need=20 one.
 
Regards,
Jerry
Subject: I GOOFED From: "Jerry Payton" gpayton880@....... Date: Tue, 30 Oct 2007 08:33:29 -0500 My apologies to the PSN Net. My last email was supposed to go to Ted Channel and not the Net. Sorry! Jerry
My apologies to the PSN Net. 
 
My last email was supposed to go to Ted Channel and not the = Net. =20 Sorry!
 
Jerry
Subject: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 31 Oct 2007 02:46:53 +0000 Hi all My earthquake computer did suffer a huge hardware failure. The motherboard in the computer did fail and I am unable to start the computer. So my sensor net is going to be partical offline for the next two days or so. My Borgarnes sensor is still online, far as I can tell, but the web page is not going to get updated while the computer is down. Now I hope it stays quiet while I am fixing this. Last time I had a hardware failure, I missed a mag 4.6 earthquake in Iceland. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: tchannel1@............ Date: Tue, 30 Oct 2007 20:59:11 -0600 Hi Jon, Well, we know what happens when someone's sensor is down for equipment failure! Good luck with your repairs. Ted ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Tuesday, October 30, 2007 8:46 PM Subject: Hardware failure Hi all My earthquake computer did suffer a huge hardware failure. The motherboard in the computer did fail and I am unable to start the computer. So my sensor net is going to be partical offline for the next two days or so. My Borgarnes sensor is still online, far as I can tell, but the web page is not going to get updated while the computer is down. Now I hope it stays quiet while I am fixing this. Last time I had a hardware failure, I missed a mag 4.6 earthquake in Iceland. Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: "Rudy Norvelle" rudy43norvelle@........... Date: Tue, 30 Oct 2007 20:10:12 -0700 Just had a nice one here East of San Jose. I don't have a seismograph. It lasted about 6-7 seconds. ----- Original Message ----- From: To: Sent: Tuesday, October 30, 2007 7:59 PM Subject: Re: Hardware failure > Hi Jon, Well, we know what happens when someone's sensor is down for > equipment failure! Good luck with your repairs. > Ted > > > ----- Original Message ----- > From: "Jón Frímann" > To: "PSN-Postlist" > Sent: Tuesday, October 30, 2007 8:46 PM > Subject: Hardware failure > > > Hi all > > My earthquake computer did suffer a huge hardware failure. The > motherboard in the computer did fail and I am unable to start the > computer. So my sensor net is going to be partical offline for the next > two days or so. My Borgarnes sensor is still online, far as I can tell, > but the web page is not going to get updated while the computer is down. > > Now I hope it stays quiet while I am fixing this. Last time I had a > hardware failure, I missed a mag 4.6 earthquake in Iceland. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://earthquakes.jonfr.com > http://www.net303.net > http://www.mobile-coverage.com/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: "Stephen Hammond" shammon1@............. Date: Tue, 30 Oct 2007 20:46:18 -0700 Email From a friend --=20 I am now living in North San Jose, just a few hundred yards from Milpitas. As you know by now, that is 11 miles from the epicenter. It was a sharp quake, with a lot of lateral motion, lasting 15-20 seconds. Since we were close and it was fairly shallow (5.5 miles), it was not a roller, but a long series of sharp jolts. The doors opened on the china hutch, some stuff fell of the desk, but nothing broke. After the major motion was over, it felt like we were on a boat on the ocean with a long series of rolling waves. Steve Hammond PSN Aptos CA. -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Rudy Norvelle Sent: Tuesday, October 30, 2007 8:10 PM To: psn-l@.............. Subject: Re: Hardware failure Just had a nice one here East of San Jose. I don't have a seismograph. It=20 lasted about 6-7 seconds. ----- Original Message -----=20 From: To: Sent: Tuesday, October 30, 2007 7:59 PM Subject: Re: Hardware failure > Hi Jon, Well, we know what happens when someone's sensor is down for > equipment failure! Good luck with your repairs. > Ted > > > ----- Original Message -----=20 > From: "J=F3n Fr=EDmann" > To: "PSN-Postlist" > Sent: Tuesday, October 30, 2007 8:46 PM > Subject: Hardware failure > > > Hi all > > My earthquake computer did suffer a huge hardware failure. The > motherboard in the computer did fail and I am unable to start the > computer. So my sensor net is going to be partical offline for the next > two days or so. My Borgarnes sensor is still online, far as I can tell, > but the web page is not going to get updated while the computer is down. > > Now I hope it stays quiet while I am fixing this. Last time I had a > hardware failure, I missed a mag 4.6 earthquake in Iceland. > > Regards. > --=20 > J=F3n Fr=EDmann > http://www.jonfr.com > http://earthquakes.jonfr.com > http://www.net303.net > http://www.mobile-coverage.com/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the=20 > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 31 Oct 2007 03:54:11 +0000 Hi all EMSC says that the San Fransico earthquake was mb5.2. I am still hopeing that Iceland gets a quiet time until I am able to fix my earthquake computer, that is going to take at least two days. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: Brad Douglas rez@.................. Date: Wed, 31 Oct 2007 04:01:32 +0000 Yup! Initial M5.6 (9km) near the Hayward Step-over on the Calaveras fault. Strong rolling for a good 10 seconds, here in Fremont, but no real damage...Amazing for such the magnitude. I noticed that all of the telemetry frequencies stopped after the quake. On Tue, 2007-10-30 at 20:10 -0700, Rudy Norvelle wrote: > Just had a nice one here East of San Jose. I don't have a seismograph. It > lasted about 6-7 seconds. > > ----- Original Message ----- > From: > Subject: Re: Hardware failure > > > Hi Jon, Well, we know what happens when someone's sensor is down for > > equipment failure! Good luck with your repairs. > > Ted -- 73, de Brad KB8UYR/6 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 31 Oct 2007 04:05:08 +0000 Hi all There was also a Mw7.0 earthquake at PAGAN REG., N. MARIANA ISLANDS at 03:30 (sorry for caps). I still hope that Iceland stays quiet until I can fix my computer. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: Pete Rowe ptrowe@......... Date: Tue, 30 Oct 2007 21:44:01 -0700 (PDT) I had lots of shaking here near Alum Rock. I was looking at my seismograph when it hit. I've seen about 10 aftershocks. None that I've felt. I have some broken glass to clean up but nothing major. Like John Muir once said: "earthquakes are grand and glorious things" Pete --- Stephen Hammond wrote: > Email From a friend -- > I am now living in North San Jose, just a few > hundred yards from > Milpitas. As you know by now, that is 11 miles from > the epicenter. It > was a sharp quake, with a lot of lateral motion, > lasting 15-20 seconds. > Since we were close and it was fairly shallow (5.5 > miles), it was not a > roller, but a long series of sharp jolts. The doors > opened on the china > hutch, some stuff fell of the desk, but nothing > broke. After the major > motion was over, it felt like we were on a boat on > the ocean with a long > series of rolling waves. > Steve Hammond PSN Aptos CA. > > -----Original Message----- > From: psn-l-request@.............. > [mailto:psn-l-request@............... > On Behalf Of Rudy Norvelle > Sent: Tuesday, October 30, 2007 8:10 PM > To: psn-l@.............. > Subject: Re: Hardware failure > > Just had a nice one here East of San Jose. I don't > have a seismograph. > It > lasted about 6-7 seconds. > > > ----- Original Message ----- > From: > To: > Sent: Tuesday, October 30, 2007 7:59 PM > Subject: Re: Hardware failure > > > > Hi Jon, Well, we know what happens when > someone's sensor is down for > > > equipment failure! Good luck with your repairs. > > Ted > > > > > > ----- Original Message ----- > > From: "Jón Frímann" > > To: "PSN-Postlist" > > Sent: Tuesday, October 30, 2007 8:46 PM > > Subject: Hardware failure > > > > > > Hi all > > > > My earthquake computer did suffer a huge hardware > failure. The > > motherboard in the computer did fail and I am > unable to start the > > computer. So my sensor net is going to be partical > offline for the > next > > two days or so. My Borgarnes sensor is still > online, far as I can > tell, > > but the web page is not going to get updated while > the computer is > down. > > > > Now I hope it stays quiet while I am fixing this. > Last time I had a > > hardware failure, I missed a mag 4.6 earthquake in > Iceland. > > > > Regards. > > -- > > Jón Frímann > > http://www.jonfr.com > > http://earthquakes.jonfr.com > > http://www.net303.net > > http://www.mobile-coverage.com/ > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with > > the body of the message (first line only): > unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with the body of > the > > message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: "Kareem of Heyjoojoo.com" system98765@............. Date: Tue, 30 Oct 2007 22:39:46 -0700 felt it in my Xterra in Walnut Creek, Ca while stopped at a signal = light. I initially thought it was the wind but was unable to locate any branches being jostled by wind. But I did see the signal light bobbing up and = down. It did seem to last for quite some time in my vehicle, clear distinct jostling with several sharp pushes. My first such experience in a car. =20 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Pete Rowe Sent: Tuesday, October 30, 2007 9:44 PM To: psn-l@.............. Subject: RE: Hardware failure I had lots of shaking here near Alum Rock. I was looking at my = seismograph when it hit. I've seen about 10 aftershocks. None that I've felt. I have some broken glass to clean up but nothing major. Like John Muir once said: "earthquakes are grand and glorious things" Pete --- Stephen Hammond wrote: > Email From a friend -- > I am now living in North San Jose, just a few hundred yards from=20 > Milpitas. As you know by now, that is 11 miles from the epicenter. =20 > It was a sharp quake, with a lot of lateral motion, lasting 15-20=20 > seconds. > Since we were close and it was fairly shallow (5.5 miles), it was not=20 > a roller, but a long series of sharp jolts. The doors opened on the=20 > china hutch, some stuff fell of the desk, but nothing broke. After the = > major motion was over, it felt like we were on a boat on the ocean=20 > with a long series of rolling waves. > Steve Hammond PSN Aptos CA. >=20 > -----Original Message----- > From: psn-l-request@.............. > [mailto:psn-l-request@............... > On Behalf Of Rudy Norvelle > Sent: Tuesday, October 30, 2007 8:10 PM > To: psn-l@.............. > Subject: Re: Hardware failure >=20 > Just had a nice one here East of San Jose. I don't have a=20 > seismograph. > It > lasted about 6-7 seconds. >=20 >=20 > ----- Original Message ----- > From: > To: > Sent: Tuesday, October 30, 2007 7:59 PM > Subject: Re: Hardware failure >=20 >=20 > > Hi Jon, Well, we know what happens when > someone's sensor is down for >=20 > > equipment failure! Good luck with your repairs. > > Ted > > > > > > ----- Original Message ----- > > From: "J=F3n Fr=EDmann" > > To: "PSN-Postlist" > > Sent: Tuesday, October 30, 2007 8:46 PM > > Subject: Hardware failure > > > > > > Hi all > > > > My earthquake computer did suffer a huge hardware > failure. The > > motherboard in the computer did fail and I am > unable to start the > > computer. So my sensor net is going to be partical > offline for the > next > > two days or so. My Borgarnes sensor is still > online, far as I can > tell, > > but the web page is not going to get updated while > the computer is > down. > > > > Now I hope it stays quiet while I am fixing this. > Last time I had a > > hardware failure, I missed a mag 4.6 earthquake in > Iceland. > > > > Regards. > > -- > > J=F3n Fr=EDmann > > http://www.jonfr.com > > http://earthquakes.jonfr.com > > http://www.net303.net > > http://www.mobile-coverage.com/ > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with > > the body of the message (first line only): > unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with the body of the > > message (first line only): unsubscribe See=20 > > http://www.seismicnet.com/maillist.html for > more information. > >=20 >=20 >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: tchannel1@............ Date: Wed, 31 Oct 2007 07:36:25 -0600 Hi Rudy, Let build one for you together. This is a great hobby. Many resources here at PSN. Happy to help you. Ted ----- Original Message ----- From: "Rudy Norvelle" To: Sent: Tuesday, October 30, 2007 9:10 PM Subject: Re: Hardware failure > Just had a nice one here East of San Jose. I don't have a seismograph. > It lasted about 6-7 seconds. > > > ----- Original Message ----- > From: > To: > Sent: Tuesday, October 30, 2007 7:59 PM > Subject: Re: Hardware failure > > >> Hi Jon, Well, we know what happens when someone's sensor is down for >> equipment failure! Good luck with your repairs. >> Ted >> >> >> ----- Original Message ----- >> From: "Jón Frímann" >> To: "PSN-Postlist" >> Sent: Tuesday, October 30, 2007 8:46 PM >> Subject: Hardware failure >> >> >> Hi all >> >> My earthquake computer did suffer a huge hardware failure. The >> motherboard in the computer did fail and I am unable to start the >> computer. So my sensor net is going to be partical offline for the next >> two days or so. My Borgarnes sensor is still online, far as I can tell, >> but the web page is not going to get updated while the computer is down. >> >> Now I hope it stays quiet while I am fixing this. Last time I had a >> hardware failure, I missed a mag 4.6 earthquake in Iceland. >> >> Regards. >> -- >> Jón Frímann >> http://www.jonfr.com >> http://earthquakes.jonfr.com >> http://www.net303.net >> http://www.mobile-coverage.com/ >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with >> the body of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: USGS seems to be one hour off From: George Bush ke6pxp@....... Date: Wed, 31 Oct 2007 11:16:41 -0700 In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while working in Winquake that the quake information download from USGS was one hour off. I had to go to the heading info and change the time from 04 UT to 03 UT??? This is the information from http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html (N. Cal Events) that Winquake uses. The main USGS web site has the correct time as does the automatic email notices they send me of new quakes. Could USGS REALLY be off one hour in the UT time listed? Or am I just doing something wrong??? George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: USGS seems to be one hour off From: "Jerry Payton" gpayton880@....... Date: Wed, 31 Oct 2007 13:26:49 -0500 I've heard some people saying that their electronic devices (DVD player, VCR's & Etc.)have already done the "Fall Back" thing which is later this year than previously. Could that be you problem? regards, Jerry ----- Original Message ----- From: George Bush To: psn-l@.............. Sent: Wednesday, October 31, 2007 1:16 PM Subject: USGS seems to be one hour off In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while working in Winquake that the quake information download from USGS was one hour off. I had to go to the heading info and change the time from 04 UT to 03 UT??? This is the information from http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html (N. Cal Events) that Winquake uses. The main USGS web site has the correct time as does the automatic email notices they send me of new quakes. Could USGS REALLY be off one hour in the UT time listed? Or am I just doing something wrong??? George __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
I've heard some people saying that their electronic devices (DVD = player,=20 VCR's & Etc.)have already done the "Fall Back" thing which is later = this=20 year than previously.  Could that be you problem?
 
regards,
Jerry
 
 
----- Original Message -----=20
From: George Bush =
Sent: Wednesday, October 31, 2007 1:16 PM
Subject: USGS seems to be one hour off

In processing the 5.6 Ml quake from Alum Rock yesterday I = noticed=20 while
working in Winquake that the quake information download from = USGS was=20 one
hour off. I had to go to the heading info and change the time = from 04 UT=20 to
03 UT??? This is the information from
http://qu= ake.wr.usgs.gov/recenteqs/Quakes/quakes0.html=20 (N. Cal Events) that
Winquake uses. The main USGS web site has the = correct=20 time as does the
automatic email notices they send me of new=20 quakes.

Could USGS REALLY be off one hour in the UT time listed? = Or am I=20 just doing
something=20 wrong???
George
___________________________________________________= _______

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: USGS seems to be one hour off From: George Bush ke6pxp@....... Date: Wed, 31 Oct 2007 12:02:36 -0700 I don't think so, it is the UTC from USGS that is wrong, not local time. At 01:26 PM 10/31/2007 -0500, you wrote: >>>> I've heard some people saying that their electronic devices (DVD player, VCR's & Etc.)have already done the "Fall Back" thing which is later this year than previously. Could that be you problem? regards, Jerry ----- Original Message ----- From: <George Bush To: <psn-l@.............. Sent: Wednesday, October 31, 2007 1:16 PM Subject: USGS seems to be one hour off In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while working in Winquake that the quake information download from USGS was one hour off. I had to go to the heading info and change the time from 04 UT to 03 UT??? This is the information from <http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html (N. Cal Events) that Winquake uses. The main USGS web site has the correct time as does the automatic email notices they send me of new quakes. Could USGS REALLY be off one hour in the UT time listed? Or am I just doing something wrong??? George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email <PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe See <http://www.seismicnet.com/maillist.html for more information. <<<<<<<< George Subject: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Wed, 31 Oct 2007 15:57:20 -0600 Hi all, Quite some time back, their was a reference (text) regarding a rough "deflection" test; where a small item (feather or something similar), was placed upon the mass of a vertical seismometer, and that displacement was a rough measure of (I think) of its crude sensitivity? Anybody have a knowledge of such; or a exact PSN email reference...or their experiences? Thanks, Meredith Lamb
Hi all,
 
Quite some time back, their was a reference (text) regarding a rough "deflection" test;
where a small item (feather or something similar), was placed upon the mass of a
vertical seismometer, and that displacement was a rough measure of (I think) of its
crude sensitivity?
 
Anybody have a knowledge of such; or a exact PSN email reference...or their
experiences?
 
Thanks, Meredith Lamb
 
 
 
 
Subject: Re: Mass deflection weight test From: "Bob Hammond" propgrinder@......... Date: Wed, 31 Oct 2007 14:06:44 -0800 http://www.geophys.uni-stuttgart.de/oldwww/seismometry/man_html/node41.html Bob PSN-Alaska http://wulik.com On Oct 31, 2007 1:57 PM, meredith lamb wrote: > Hi all, > > Quite some time back, their was a reference (text) regarding a rough > "deflection" test; > where a small item (feather or something similar), was placed upon the > mass of a > vertical seismometer, and that displacement was a rough measure of (I > think) of its > crude sensitivity? > > Anybody have a knowledge of such; or a exact PSN email reference...or > their > experiences? > > Thanks, Meredith Lamb > > > > >
 
Bob
PSN-Alaska
On Oct 31, 2007 1:57 PM, meredith lamb <paleoartifact@.........> wrote:
Hi all,
 
Quite some time back, their was a reference (text) regarding a rough "deflection" test;
where a small item (feather or something similar), was placed upon the mass of a
vertical seismometer, and that displacement was a rough measure of (I think) of its
crude sensitivity?
 
Anybody have a knowledge of such; or a exact PSN email reference...or their
experiences?
 
Thanks, Meredith Lamb
 
 
 
 

Subject: Re: Mass deflection weight test From: tchannel1@............ Date: Wed, 31 Oct 2007 16:16:03 -0600 Hi Meredith, I have seen a similar test, using a small folded piece of = paper on a thread. The thread was pulled which removed the small piece = of paper from the pendulum arm. This was one of the AS1 wed sites, I think. Ted ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Wednesday, October 31, 2007 3:57 PM Subject: Mass deflection weight test Hi all, Quite some time back, their was a reference (text) regarding a rough = "deflection" test;=20 where a small item (feather or something similar), was placed upon the = mass of a vertical seismometer, and that displacement was a rough measure of (I = think) of its crude sensitivity? Anybody have a knowledge of such; or a exact PSN email reference...or = their experiences? Thanks, Meredith Lamb
Hi Meredith,  I have seen a = similar test,=20 using a small folded piece of paper on a thread.  The thread was = pulled=20 which removed the small piece of paper from the pendulum = arm.
This was one of the AS1 wed sites, I=20 think.
Ted
----- Original Message -----
From:=20 meredith lamb
Sent: Wednesday, October 31, = 2007 3:57=20 PM
Subject: Mass deflection weight = test

Hi all,
 
Quite some time back, their was a reference (text) regarding a = rough=20 "deflection" test;
where a small item (feather or something similar), was placed = upon the=20 mass of a
vertical seismometer, and that displacement was a rough measure = of (I=20 think) of its
crude sensitivity?
 
Anybody have a knowledge of such; or a exact PSN email = reference...or=20 their
experiences?
 
Thanks, Meredith Lamb
 
 
 
 
Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Wed, 31 Oct 2007 20:01:30 EDT In a message dated 31/10/2007, paleoartifact@......... writes: Quite some time back, their was a reference (text) regarding a rough "deflection" test; where a small item (feather or something similar), was placed upon the mass of a vertical seismometer, and that displacement was a rough measure of (I think) of its crude sensitivity? Hi Meredith, Weight lift calibration is used on AS-1 seismometers. See links from _http://jclahr.com/science/psn/as1/_ (http://jclahr.com/science/psn/as1/) Far from being crude, it should be accurate at least to a few%. I favour using weights made from known lengths and diameters of copper wire, bent to give three point contacts. You can use fine nylon fishing line to lift the weight. Sewing thread tends to twist. You can also calibrate horizontal seismometers using a wire weight suspended on a 90 deg V silk / cotton thread. Having set the system up, you release the mass by burning the thread. Regards, Chris
In a message dated 31/10/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Quite some time back, their was a reference (text) regarding a rough=20 "deflection" test;
where a small item (feather or something similar), was placed upon th= e=20 mass of a
vertical seismometer, and that displacement was a rough measure of (I= =20 think) of its
crude sensitivity?
Hi Meredith,
 
    Weight lift calibration is used on AS-1=20 seismometers. See links from  http://jclahr.com/science/psn/as= 1/
    Far from being crude, it should be accurate at=20 least to a few%. I favour using weights made from known lengths and diameter= s of=20 copper wire, bent to give three point contacts. You can use fine nylon fishi= ng=20 line to lift the weight. Sewing thread tends to twist.
    You can also calibrate horizontal seismometers=20 using a wire weight suspended on a 90 deg V silk / cotton thread. Having set= the=20 system up, you release the mass by burning the thread.  
 
    Regards,
 
    Chris
Subject: Earthquake experiences From: "Kay Wyatt" kwyatt@............. Date: Wed, 31 Oct 2007 19:37:47 -0700 Folks, I confess that I enjoyed hearing about experiences that many of you = shared regarding yesterday's earthquakes. One question that I am asked = time after time by our young budding students is "what does an = earthquake feel like". Having come from Oklahoma and recently retired = to Oregon, being in an earthquake is not one of my personal experiences. If any of you would like to share your personal experiences with my = students, I would be delighted to hear from you. You can email me = directly at kwyatt@............. if you wish. Thanks, also, to all of you who have provided feedback regarding = seismometers suitable in an educational environment. Kay Wyatt
Folks,
 
I confess that I enjoyed hearing about experiences = that many=20 of you shared regarding yesterday's earthquakes.  One question that = I am=20 asked time after time by our young budding students is "what does an = earthquake=20 feel like".  Having come from Oklahoma and recently retired to = Oregon,=20 being in an earthquake is not one of my personal = experiences.
 
If any of you would like to share your personal = experiences=20 with my students, I would be delighted to hear from you.  You can = email me=20 directly at kwyatt@............. if=20 you wish.
 
Thanks, also, to all of you who have provided = feedback=20 regarding seismometers suitable in an educational = environment.
 
Kay Wyatt
 
Subject: Re: Earthquake experiences From: "Bob Hammond" propgrinder@......... Date: Wed, 31 Oct 2007 18:53:43 -0800 Kay, Here's a link to my web page and personal accounts of people feeling the M 7.9 (revised to M 8.2, I think) earthquake of November 3, 2002. The first one is my wife's personal account of the quake in our house in Fairbanks. The rest of the felt reports were compiled by a friend who was the Denali National Park Geologist at the time of the quake. http://wulik.com/descript.htm This might be of interest and use to your students. Regards, Bob Hammond PSN-Alaska http://wulik.com On Oct 31, 2007 6:37 PM, Kay Wyatt wrote: > Folks, > > I confess that I enjoyed hearing about experiences that many of you shared > regarding yesterday's earthquakes. One question that I am asked time after > time by our young budding students is "what does an earthquake feel like". > Having come from Oklahoma and recently retired to Oregon, being in an > earthquake is not one of my personal experiences. > > If any of you would like to share your personal experiences with my > students, I would be delighted to hear from you. You can email me directly > at kwyatt@............. if you wish. > > Thanks, also, to all of you who have provided feedback regarding > seismometers suitable in an educational environment. > > Kay Wyatt > > Kay,

Here's a link to my web page and personal accounts of people feeling the M 7.9 (revised to M 8.2, I think) earthquake of November 3, 2002.  The first one is my wife's personal account of the quake in our house in Fairbanks.  The rest of the felt reports were compiled by a friend who was the Denali National Park Geologist at the time of the quake.

http://wulik.com/descript.htm

This might be of interest and use to your students.

Regards,

Bob Hammond
PSN-Alaska
http://wulik.com



On Oct 31, 2007 6:37 PM, Kay Wyatt <kwyatt@.............> wrote:
Folks,
 
I confess that I enjoyed hearing about experiences that many of you shared regarding yesterday's earthquakes.  One question that I am asked time after time by our young budding students is "what does an earthquake feel like".  Having come from Oklahoma and recently retired to Oregon, being in an earthquake is not one of my personal experiences.
 
If any of you would like to share your personal experiences with my students, I would be delighted to hear from you.  You can email me directly at kwyatt@............. if you wish.
 
Thanks, also, to all of you who have provided feedback regarding seismometers suitable in an educational environment.
 
Kay Wyatt
 

Subject: Re: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Wed, 31 Oct 2007 22:00:19 -0600 Hi Chris and all, Thanks for all the helpful references! I was looking for a test that would roughly indicate pivot sensitivity; but where, there is no pickup coil (electronics), dampening etc....i.e., a "base" test of the instruments pivot/boom/mass in its unfinished state, just to evaluate whether the setup is worth further pursuing. After going through John Lahr's web site...I "gather" that if; say a bond paper item of about ~2" x 1/2" is laid atop the mass, and one can VISUALLY see a immediate deflection of the mass; then the sensitivity must be quite good. Does this sound logical; or maybe I'am missing something? The test vertical instrument here is using acouple hard drive disk/s inner hole circle surfaces with the axis being a 1/4" rod...i.e, a rolling pivot; laid out somewhat like the Georgia Tech vertical "demonstrator" seismometer...but not using flexure strips as the pivot. I could see roughly a initial 1/16" deflection. Meredith Lamb On 10/31/07, ChrisAtUpw@....... wrote: > > In a message dated 31/10/2007, paleoartifact@......... writes: > > Quite some time back, their was a reference (text) regarding a rough > "deflection" test; > where a small item (feather or something similar), was placed upon the > mass of a > vertical seismometer, and that displacement was a rough measure of (I > think) of its > crude sensitivity? > > Hi Meredith, > > Weight lift calibration is used on AS-1 seismometers. See links from > http://jclahr.com/science/psn/as1/ > Far from being crude, it should be accurate at least to a few%. I > favour using weights made from known lengths and diameters of copper wire, > bent to give three point contacts. You can use fine nylon fishing line to > lift the weight. Sewing thread tends to twist. > You can also calibrate horizontal seismometers using a wire weight > suspended on a 90 deg V silk / cotton thread. Having set the system up, you > release the mass by burning the thread. > > Regards, > > Chris >
Hi Chris and all,
 
Thanks for all the helpful references!  I was looking for a test that would roughly indicate
pivot sensitivity; but where, there is no pickup coil (electronics), dampening etc....i.e.,
a "base" test of the instruments pivot/boom/mass in its unfinished state, just to
evaluate whether the setup is worth further pursuing.
 
After going through John Lahr's web site...I "gather" that if; say a bond paper item of
about ~2" x 1/2" is laid atop the mass, and one can VISUALLY see a immediate
deflection of the mass; then the sensitivity must be quite good.  Does this sound
logical; or maybe I'am missing something?
 
The test vertical instrument here is using acouple hard drive disk/s inner hole circle surfaces
with the axis being a 1/4" rod...i.e, a rolling pivot; laid out somewhat like the Georgia
Tech vertical "demonstrator" seismometer...but not using flexure strips as the pivot.
I could see roughly a initial 1/16" deflection. 
 
Meredith Lamb

 
On 10/31/07, ChrisAtUpw@....... <ChrisAtUpw@.......> wrote:
In a message dated 31/10/2007, paleoartifact@......... writes:
Quite some time back, their was a reference (text) regarding a rough "deflection" test;
where a small item (feather or something similar), was placed upon the mass of a
vertical seismometer, and that displacement was a rough measure of (I think) of its
crude sensitivity?
Hi Meredith,
 
    Weight lift calibration is used on AS-1 seismometers. See links from  http://jclahr.com/science/psn/as1/
    Far from being crude, it should be accurate at least to a few%. I favour using weights made from known lengths and diameters of copper wire, bent to give three point contacts. You can use fine nylon fishing line to lift the weight. Sewing thread tends to twist.
    You can also calibrate horizontal seismometers using a wire weight suspended on a 90 deg V silk / cotton thread. Having set the system up, you release the mass by burning the thread.  
 
    Regards,
 
    Chris

Subject: Re: Mass deflection weight test From: John Lahr johnjan@........ Date: Wed, 31 Oct 2007 22:24:01 -0700 Meredith, The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338 gm. I don't think the deflection of the boom could be seen with the eye, but I haven't tried. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 01 Nov 2007 12:45:36 +0000 Hi all I am almost done with my repairs. Now I just have to re-install windows 2000 and setup the computer. On a side note, the serial port (Com1 & 2) are dissapearing from the motherboard. The new motherboard that I got dosen't even have a Com port, I needed to get a extra plug for that. I do however have usb to serial converter, but in the future I guess earthquake hardware needs to have usb ports also. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: ian ian@........... Date: Thu, 01 Nov 2007 13:13:37 +0000 you just missed a mag 3.6 in your back yard at 12:47 gmt! To replace com ports, you could look at terminal servers, ie: http://www.perle.com/ They come with software that makes them look like com ports. Might be a bit pricey though. Cheers Ian Jón Frímann wrote: >Hi all > >I am almost done with my repairs. Now I just have to re-install windows >2000 and setup the computer. > >On a side note, the serial port (Com1 & 2) are dissapearing from the >motherboard. The new motherboard that I got dosen't even have a Com >port, I needed to get a extra plug for that. I do however have usb to >serial converter, but in the future I guess earthquake hardware needs to >have usb ports also. > >Regards. > > -- you just missed a mag 3.6 in your back yard at 12:47 gmt!

To replace com ports, you could look at terminal servers, ie: http://www.perle.com/  They come with software that makes them look like com ports.  Might be a bit pricey though.

Cheers

Ian

Jón Frímann wrote:
Hi all

I am almost done with my repairs. Now I just have to re-install windows
2000 and setup the computer.

On a side note, the serial port (Com1 & 2) are dissapearing from the
motherboard. The new motherboard that I got dosen't even have a Com
port, I needed to get a extra plug for that. I do however have usb to
serial converter, but in the future I guess earthquake hardware needs to
have usb ports also.

Regards.

--

Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 01 Nov 2007 13:18:29 +0000 Hi I just noticed the ML3.6 earthquake, only my hvt station did miss it. My Borgarnes station is still working even if it is not online, it did record it. I will get the earthquake manually later today. But this always happens when something fails.... Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake experiences From: "Jerry Payton" gpayton880@....... Date: Thu, 1 Nov 2007 08:48:33 -0500 Thanks, also, to all of you who have provided feedback regarding seismometers suitable in an educational environment. Dr. Wyatt, please share any other sources of seismometers give to you, other those already mentioned: AS-1, VM II and etc., to us low budgeted "Amateur Nerds" out here. Thanks for your devotion to the children. Regards, Jerry
Thanks, also, to all of you who have provided = feedback=20 regarding seismometers suitable in an educational = environment.
 
Dr. Wyatt, please share any other sources of = seismometers give to you, other those already mentioned: AS-1, VM II and = etc.,=20 to us low budgeted "Amateur Nerds" out here.  Thanks for your = devotion to=20 the children. 
 
Regards,
Jerry
Subject: Re: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Thu, 1 Nov 2007 09:26:53 -0600 Hi John, OK on the correction. Per your web site, that particular "item" had more to it, than what we've texted here of course. I used a mass head reference object and eyeballed it when putting the paper size I used down on the mass. Suspect one might see the deflection of the AS-1 mass also if they "look" for it as described, but without dampening or the coil hooked up; in free mass response. Its rather tough to gauge any verticals sensitivity without further completing the whole assembly....they are much more difficult to adjust and maintain overall. Meredith On 10/31/07, John Lahr wrote: > > Meredith, > > The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338 > gm. I don't think the > deflection of the boom could be seen with the eye, but I haven't tried. > > John > > >
Hi John,
 
OK on the correction.  Per your web site, that particular "item" had more to it, than
what we've texted here of course.  I used a mass head reference object and eyeballed it
when putting the paper size I used down on the mass.  Suspect one might see the
deflection of the AS-1 mass also if they "look" for it as described, but without 
dampening or the coil hooked up; in free mass response.  Its rather tough to
gauge any verticals sensitivity without further completing the whole assembly....they
are much more difficult to adjust and maintain overall. 
 
Meredith             

 
On 10/31/07, John Lahr <johnjan@........> wrote:
Meredith,

The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338
gm.  I don't think the
deflection of the boom could be seen with the eye, but I haven't tried.

John


Subject: Fwd: RE: Re: USGS seems to be one hour off From: John Lahr johnjan@........ Date: Thu, 01 Nov 2007 08:39:58 -0700 Here's the word that I received from Menlo Park on the timing error. There seems to be no error at all on the web site. If the events from this page: http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html which shows the time in PDT is imported into WinQuake and converted by WinQuake into UT, then the conversion could be in error if the computer has already switched from PDT to PST. I'm running some computers with Win98SE and have yet to figure out how to change the switch over time from PDT to PST. Cheers, John >Hi John, > >I don't understand the problem. The link he references >http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >shows time in PDT, which is correct. The page >http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >shows both UTC and PDT, which are both correct. > >-David > >------------------------------------------------------- > >-----Original Message----- >From: John Lahr [mailto:johnjan@......... >Sent: Wednesday, October 31, 2007 3:09 PM >To: David O >Subject: Fwd: Re: USGS seems to be one hour off > >FYI, > >John > > >X-Original-To: jclahr > >Delivered-To: jclahr@.................. > >From: "Jerry Payton" > >To: > >Subject: Re: USGS seems to be one hour off > >Date: Wed, 31 Oct 2007 13:26:49 -0500 > >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 > >Reply-To: psn-l@.............. > >Sender: psn-l-request@.............. > >X-RCPT-TO: > >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 > >X-SA-USERIDNR: 3394894 > >X-SA-MPREASON: sender enabled (gpayton880@........ > > > >I've heard some people saying that their electronic devices (DVD > >player, VCR's & Etc.)have already done the "Fall Back" thing which > >is later this year than previously. Could that be you problem? > > > >regards, > >Jerry > > > > > >----- Original Message ----- > >From: George Bush > >To: psn-l@.............. > >Sent: Wednesday, October 31, 2007 1:16 PM > >Subject: USGS seems to be one hour off > > > >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while > >working in Winquake that the quake information download from USGS was one > >hour off. I had to go to the heading info and change the time from 04 UT to > >03 UT??? This is the information from > >http://quak > e.wr.usgs.gov/recenteqs/Quakes/quakes0.html > >(N. Cal Events) that > >Winquake uses. The main USGS web site has the correct time as does the > >automatic email notices they send me of new quakes. > > > >Could USGS REALLY be off one hour in the UT time listed? Or am I just doing > >something wrong??? > >George > >__________________________________________________________ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: RE: Re: USGS seems to be one hour off From: "Erich Kern" efkern@............. Date: Thu, 1 Nov 2007 09:00:43 -0700 Another possibility is that the UK switched from BST (British Summer = Time) to standard time (GMT) this past Sunday. If someone was looking at = the UK domestic clock instead of the UTC / GMT clock, that may account = for it. Not saying that's what happened, just a possibility. Erich ----- Original Message -----=20 From: John Lahr=20 To: psn-l@................. Sent: Thursday, November 01, 2007 8:39 AM Subject: Fwd: RE: Re: USGS seems to be one hour off Here's the word that I received from Menlo Park on the timing error. There seems to be no error at all on the web site. If the events from this page: http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html which shows the time in PDT is imported into WinQuake and converted by WinQuake into UT, then the conversion could be in error if the computer has already switched from PDT to PST. I'm running some computers with Win98SE and have yet to figure out how to change the switch over time from PDT to PST. Cheers, John >Hi John, > >I don't understand the problem. The link he references >http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >shows time in PDT, which is correct. The page >http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >shows both UTC and PDT, which are both correct. > >-David > >------------------------------------------------------- > >-----Original Message----- >From: John Lahr [mailto:johnjan@......... >Sent: Wednesday, October 31, 2007 3:09 PM >To: David O >Subject: Fwd: Re: USGS seems to be one hour off > >FYI, > >John > > >X-Original-To: jclahr > >Delivered-To: jclahr@.................. > >From: "Jerry Payton" > >To: > >Subject: Re: USGS seems to be one hour off > >Date: Wed, 31 Oct 2007 13:26:49 -0500 > >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 > >Reply-To: psn-l@.............. > >Sender: psn-l-request@.............. > >X-RCPT-TO: > >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 > >X-SA-USERIDNR: 3394894 > >X-SA-MPREASON: sender enabled (gpayton880@........ > > > >I've heard some people saying that their electronic devices (DVD > >player, VCR's & Etc.)have already done the "Fall Back" thing which > >is later this year than previously. Could that be you problem? > > > >regards, > >Jerry > > > > > >----- Original Message ----- > >From: George Bush > >To: psn-l@.............. > >Sent: Wednesday, October 31, 2007 1:16 PM > >Subject: USGS seems to be one hour off > > > >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed = while > >working in Winquake that the quake information download from USGS was = one > >hour off. I had to go to the heading info and change the time from 04 = UT to > >03 UT??? This is the information from > >http://quak=20 > e.wr.usgs.gov/recenteqs/Quakes/quakes0.html > >(N. Cal Events) that > >Winquake uses. The main USGS web site has the correct time as does = the > >automatic email notices they send me of new quakes. > > > >Could USGS REALLY be off one hour in the UT time listed? Or am I just = doing > >something wrong??? > >George > >__________________________________________________________ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
 
Another possibility is that the UK switched from = BST=20 (British Summer Time) to standard time (GMT) this past Sunday. If = someone was=20 looking at the UK domestic clock instead of the UTC / GMT clock, that = may=20 account for it.
 
Not saying that's what happened, just a=20 possibility.
 
Erich
 
 
----- Original Message -----=20
From: John Lahr =
Sent: Thursday, November 01, 2007 8:39 AM
Subject: Fwd: RE: Re: USGS seems to be one hour = off

Here's the word that I received from Menlo Park on the = timing=20 error.

There seems to be no error at all on the web = site.

If the=20 events from this page:
http://qu= ake.wr.usgs.gov/recenteqs/Quakes/quakes0.html
which=20 shows the time in PDT is imported into WinQuake and converted
by = WinQuake=20 into UT, then the conversion could be in error if the
computer has = already=20 switched from PDT to PST.  I'm running some
computers with = Win98SE and=20 have yet to figure out how to change the
switch over time from PDT to = PST.

Cheers,
John

>Hi John,
>
>I don't=20 understand the problem. The link he=20 references
>http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html<= BR>>shows=20 time in PDT, which is correct.  The=20 page
>http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm
&= gt;shows=20 both UTC and PDT, which are both=20 correct.
>
>-David
>
>---------------------------= ----------------------------
>
>-----Original=20 Message-----
>From: John Lahr = [mailto:johnjan@.........
>Sent:=20 Wednesday, October 31, 2007 3:09 PM
>To: David O
>Subject: = Fwd: Re:=20 USGS seems to be one hour=20 off
>
>FYI,
>
>John
>
> = >X-Original-To:=20 jclahr
> >Delivered-To: jclahr@..................>=20 >From: "Jerry Payton" <gpayton880@.......>
> = >To:=20 <psn-l@..............>
>= =20 >Subject: Re: USGS seems to be one hour off
> >Date: Wed, 31 = Oct=20 2007 13:26:49 -0500
> >X-Mailer: Microsoft Outlook Express=20 6.00.2900.3138
> >Reply-To: psn-l@..............
> = >Sender:=20 psn-l-request@...............
>=20 >X-RCPT-TO: <johnjan@........>
>=20 >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000
>=20 >X-SA-USERIDNR: 3394894
> >X-SA-MPREASON: sender enabled (gpayton880@.......)
> = >
>=20 >I've heard some people saying that their electronic devices = (DVD
>=20 >player, VCR's & Etc.)have already done the "Fall Back" thing=20 which
> >is later this year than previously.  Could that = be you=20 problem?
> >
> >regards,
> >Jerry
>=20 >
> >
> >----- Original Message -----
> = >From:=20 <George">mailto:ke6pxp@.......>George= =20 Bush
> >To: <psn-l@..............">mailto:psn-l@we= btronics.com>psn-l@..............
>=20 >Sent: Wednesday, October 31, 2007 1:16 PM
> >Subject: USGS = seems to=20 be one hour off
> >
> >In processing the 5.6 Ml quake = from=20 Alum Rock yesterday I noticed while
> >working in Winquake that = the=20 quake information download from USGS was one
> >hour off. I had = to go=20 to the heading info and change the time from 04 UT to
> >03 = UT??? This=20 is the information from
> ><http://qua= k">http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html>http://quak<= /A>=20
> e.wr.usgs.gov/recenteqs/Quakes/quakes0.html
> >(N. Cal = Events)=20 that
> >Winquake uses. The main USGS web site has the correct = time as=20 does the
> >automatic email notices they send me of new = quakes.
>=20 >
> >Could USGS REALLY be off one hour in the UT time = listed? Or am=20 I just doing
> >something wrong???
> >George
>=20 >__________________________________________________________

__________________________________________________________

Public= =20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information. Subject: Re: Fwd: RE: Re: USGS seems to be one hour off From: George Bush ke6pxp@....... Date: Thu, 01 Nov 2007 09:51:25 -0700 I agree, there is no error on the web site. Also I know about the PDT time problem, but this is a USGS file and it reports time in UT and it was wrong when downloaded into Winquake???? At 08:39 AM 11/1/2007 -0700, you wrote: >Here's the word that I received from Menlo Park on the timing error. > >There seems to be no error at all on the web site. > >If the events from this page: >http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >which shows the time in PDT is imported into WinQuake and converted >by WinQuake into UT, then the conversion could be in error if the >computer has already switched from PDT to PST. I'm running some >computers with Win98SE and have yet to figure out how to change the >switch over time from PDT to PST. > >Cheers, >John > >>Hi John, >> >>I don't understand the problem. The link he references >>http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >>shows time in PDT, which is correct. The page >>http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >>shows both UTC and PDT, which are both correct. >> >>-David >> >>------------------------------------------------------- >> >>-----Original Message----- >>From: John Lahr [mailto:johnjan@......... >>Sent: Wednesday, October 31, 2007 3:09 PM >>To: David O >>Subject: Fwd: Re: USGS seems to be one hour off >> >>FYI, >> >>John >> >> >X-Original-To: jclahr >> >Delivered-To: jclahr@.................. >> >From: "Jerry Payton" >> >To: >> >Subject: Re: USGS seems to be one hour off >> >Date: Wed, 31 Oct 2007 13:26:49 -0500 >> >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 >> >Reply-To: psn-l@.............. >> >Sender: psn-l-request@.............. >> >X-RCPT-TO: >> >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 >> >X-SA-USERIDNR: 3394894 >> >X-SA-MPREASON: sender enabled (gpayton880@........ >> > >> >I've heard some people saying that their electronic devices (DVD >> >player, VCR's & Etc.)have already done the "Fall Back" thing which >> >is later this year than previously. Could that be you problem? >> > >> >regards, >> >Jerry >> > >> > >> >----- Original Message ----- >> >From: George Bush >> >To: psn-l@.............. >> >Sent: Wednesday, October 31, 2007 1:16 PM >> >Subject: USGS seems to be one hour off >> > >> >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while >> >working in Winquake that the quake information download from USGS was one >> >hour off. I had to go to the heading info and change the time from 04 UT to >> >03 UT??? This is the information from >> >http://quak >> e.wr.usgs.gov/recenteqs/Quakes/quakes0.html >> >(N. Cal Events) that >> >Winquake uses. The main USGS web site has the correct time as does the >> >automatic email notices they send me of new quakes. >> > >> >Could USGS REALLY be off one hour in the UT time listed? Or am I just doing >> >something wrong??? >> >George >> >__________________________________________________________ > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 01 Nov 2007 17:36:36 +0000 Hi all My earthquake computer is back in action. More powerful then ever, it now r= uns AMD 64bit 1.8Ghz CPU with 1GB ram. I did record the M3.6 earthquake on the Borgarnes station, I have send in t= he data now. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fwd: RE: Re: USGS seems to be one hour off From: Stephen & Kathy skmort@............ Date: Thu, 01 Nov 2007 11:12:30 -0700 Here is a link to a win98 daylight savings patch that worked for me! http://www.intelliadmin.com/DaylightSavingNotice.asp?File=DaylightSavingFix98.exe Stephen PSN Station # 55 John Lahr wrote: > Here's the word that I received from Menlo Park on the timing error. > > There seems to be no error at all on the web site. > > If the events from this page: > http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html > which shows the time in PDT is imported into WinQuake and converted > by WinQuake into UT, then the conversion could be in error if the > computer has already switched from PDT to PST. I'm running some > computers with Win98SE and have yet to figure out how to change the > switch over time from PDT to PST. > > Cheers, > John > >> Hi John, >> >> I don't understand the problem. The link he references >> http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >> shows time in PDT, which is correct. The page >> http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >> shows both UTC and PDT, which are both correct. >> >> -David >> >> ------------------------------------------------------- >> >> -----Original Message----- >> From: John Lahr [mailto:johnjan@......... >> Sent: Wednesday, October 31, 2007 3:09 PM >> To: David O >> Subject: Fwd: Re: USGS seems to be one hour off >> >> FYI, >> >> John >> >> >X-Original-To: jclahr >> >Delivered-To: jclahr@.................. >> >From: "Jerry Payton" >> >To: >> >Subject: Re: USGS seems to be one hour off >> >Date: Wed, 31 Oct 2007 13:26:49 -0500 >> >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 >> >Reply-To: psn-l@.............. >> >Sender: psn-l-request@.............. >> >X-RCPT-TO: >> >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 >> >X-SA-USERIDNR: 3394894 >> >X-SA-MPREASON: sender enabled (gpayton880@........ >> > >> >I've heard some people saying that their electronic devices (DVD >> >player, VCR's & Etc.)have already done the "Fall Back" thing which >> >is later this year than previously. Could that be you problem? >> > >> >regards, >> >Jerry >> > >> > >> >----- Original Message ----- >> >From: George Bush >> >To: psn-l@.............. >> >Sent: Wednesday, October 31, 2007 1:16 PM >> >Subject: USGS seems to be one hour off >> > >> >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while >> >working in Winquake that the quake information download from USGS >> was one >> >hour off. I had to go to the heading info and change the time from >> 04 UT to >> >03 UT??? This is the information from >> >http://quak >> e.wr.usgs.gov/recenteqs/Quakes/quakes0.html >> >(N. Cal Events) that >> >Winquake uses. The main USGS web site has the correct time as does the >> >automatic email notices they send me of new quakes. >> > >> >Could USGS REALLY be off one hour in the UT time listed? Or am I >> just doing >> >something wrong??? >> >George >> >__________________________________________________________ > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > Here is a link to a win98 daylight savings patch that worked for me!

http://www.intelliadmin.com/DaylightSavingNotice.asp?File=DaylightSavingFix98.exe

   Stephen
   PSN Station # 55

John Lahr wrote:
Here's the word that I received from Menlo Park on the timing error.

There seems to be no error at all on the web site.

If the events from this page:
http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html
which shows the time in PDT is imported into WinQuake and converted
by WinQuake into UT, then the conversion could be in error if the
computer has already switched from PDT to PST.  I'm running some
computers with Win98SE and have yet to figure out how to change the
switch over time from PDT to PST.

Cheers,
John

Hi John,

I don't understand the problem. The link he references
http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html
shows time in PDT, which is correct.  The page
http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm
shows both UTC and PDT, which are both correct.

-David

-------------------------------------------------------

-----Original Message-----
From: John Lahr [mailto:johnjan@........]
Sent: Wednesday, October 31, 2007 3:09 PM
To: David O
Subject: Fwd: Re: USGS seems to be one hour off

FYI,

John

>X-Original-To: jclahr
>Delivered-To: jclahr@..................
>From: "Jerry Payton" <gpayton880@.......>
>To: <psn-l@..............>
>Subject: Re: USGS seems to be one hour off
>Date: Wed, 31 Oct 2007 13:26:49 -0500
>X-Mailer: Microsoft Outlook Express 6.00.2900.3138
>Reply-To: psn-l@..............
>Sender: psn-l-request@..............
>X-RCPT-TO: <johnjan@........>
>X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000
>X-SA-USERIDNR: 3394894
>X-SA-MPREASON: sender enabled (gpayton880@.......)
>
>I've heard some people saying that their electronic devices (DVD
>player, VCR's & Etc.)have already done the "Fall Back" thing which
>is later this year than previously.  Could that be you problem?
>
>regards,
>Jerry
>
>
>----- Original Message -----
>From: <mailto:ke6pxp@.......>George Bush
>To: <mailto:psn-l@..............>psn-l@..............
>Sent: Wednesday, October 31, 2007 1:16 PM
>Subject: USGS seems to be one hour off
>
>In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while
>working in Winquake that the quake information download from USGS was one
>hour off. I had to go to the heading info and change the time from 04 UT to
>03 UT??? This is the information from
><http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html>http://quak e.wr.usgs.gov/recenteqs/Quakes/quakes0.html
>(N. Cal Events) that
>Winquake uses. The main USGS web site has the correct time as does the
>automatic email notices they send me of new quakes.
>
>Could USGS REALLY be off one hour in the UT time listed? Or am I just doing
>something wrong???
>George
>__________________________________________________________


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.


Subject: Re: Mass deflection weight test From: John Lahr johnjan@........ Date: Thu, 01 Nov 2007 11:46:23 -0700 Hi Meredith, There are two issues involved. One is the absolute deflection due to adding a weight and the other is the electronic response, once some motion sensor has been applied. The absolute deflection when a weight is added is equivalent to changing the acceleration of gravity, which is also equivalent to applying a constant acceleration. The deflection will be a function of the free period; the greater the period the greater the deflection. This assumes that there is no friction at the hinge. To test various hinges, one would want a very long period pendulum. Then a very small weight should cause a known, specific deflection. If there is less deflection, then the cause must be friction. Usually the term sensitivity relates to the electronic output per unit of motion, measured as displacement or velocity or acceleration at a given period. Cheers, John At 08:26 AM 11/1/2007, you wrote: >Hi John, > >OK on the correction. Per your web site, that particular "item" had >more to it, than >what we've texted here of course. I used a mass head reference >object and eyeballed it >when putting the paper size I used down on the mass. Suspect one >might see the >deflection of the AS-1 mass also if they "look" for it as described, >but without >dampening or the coil hooked up; in free mass response. Its rather tough to >gauge any verticals sensitivity without further completing the whole >assembly....they >are much more difficult to adjust and maintain overall. > >Meredith > > >On 10/31/07, John Lahr <johnjan@........> wrote: >Meredith, > >The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338 >gm. I don't think the >deflection of the boom could be seen with the eye, but I haven't tried. > >John > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Thu, 1 Nov 2007 15:03:20 EDT In a message dated 01/11/2007, johnjan@........ writes: There are two issues involved. One is the absolute deflection due to adding a weight and the other is the electronic response, once some motion sensor has been applied. Hi John, I find it easier to cut a measured length of Copper wire and bend it so that it gives a three point contact - a small U loop and a larger U loop at right angles to it. You can look up the weight either in wire tables or by the diameter for that gauge and the density of Copper. Regards, Chris
In a message dated 01/11/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>There=20 are two issues involved.  One is the absolute deflection due to=20
adding a weight and the other is the electronic response, once some=20
motion sensor has been applied.
Hi John,
 
    I find it easier to cut a measured length of Co= pper=20 wire and bend it so that it gives a three point contact - a small U loop and= a=20 larger U loop at right angles to it. You can look up the weight either in wi= re=20 tables or by the diameter for that gauge and the density of Copper.
 
    Regards,
 
    Chris
Subject: Re: Mass deflection weight test From: John Lahr johnjan@........ Date: Thu, 01 Nov 2007 12:49:36 -0700 That's a good idea. Is there a good wire table on line that can be used? John At 12:03 PM 11/1/2007, you wrote: >In a message dated 01/11/2007, johnjan@........ writes: >There are two issues involved. One is the absolute deflection due to >adding a weight and the other is the electronic response, once some >motion sensor has been applied. > >Hi John, > > I find it easier to cut a measured length of Copper wire and > bend it so that it gives a three point contact - a small U loop and > a larger U loop at right angles to it. You can look up the weight > either in wire tables or by the diameter for that gauge and the > density of Copper. > > Regards, > > Chris __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Thu, 1 Nov 2007 16:19:19 -0600 Hi John, OK on the email. In a "maintenance" sense, it would seem appropriate to use the known test results, per each seismometer; to check on the pivot wear sporadically. I would think that if would be helpful. I would guess that knife edge, razor edge pivots would show the most wear/friction, followed by perhaps ball bearings....with my test hinge having its own particular potential problems, like lint/dirt getting in the rolling path etc. Perhaps the best would be a true crossed rod pivot....but as far as a vertical seismo...I've yet to "find" the "common" material to be able to do that. Meredith On 11/1/07, John Lahr wrote: > > Hi Meredith, > > There are two issues involved. One is the absolute deflection due to > adding a weight and the other is the electronic response, once some > motion sensor has been applied. > > The absolute deflection when a weight is added is equivalent to > changing the acceleration of gravity, which is also equivalent to > applying a constant acceleration. The deflection will be a function > of the free period; the greater the period the greater the > deflection. This assumes that there is no friction at the hinge. To > test various hinges, one would want a very long period > pendulum. Then a very small weight should cause a known, specific > deflection. If there is less deflection, then the cause must be friction. > > Usually the term sensitivity relates to the electronic output per > unit of motion, measured as displacement or velocity or acceleration > at a given period. > > Cheers, > John > > >
Hi John,
 
OK on the email.  In a "maintenance" sense, it would seem appropriate to
use the known test results, per each seismometer; to check on the pivot
wear sporadically.  I would think that if would be helpful.  I would guess that
knife edge, razor edge pivots would show the most wear/friction, followed by
perhaps ball bearings....with my test hinge having its own particular potential
problems, like lint/dirt getting in the rolling path etc.  Perhaps the best would
be a true crossed rod pivot....but as far as a vertical seismo...I've yet to "find" the
"common" material to be able to do that.
 
Meredith
 
 
On 11/1/07, John Lahr <johnjan@........> wrote:
Hi Meredith,

There are two issues involved.  One is the absolute deflection due to
adding a weight and the other is the electronic response, once some
motion sensor has been applied.

The absolute deflection when a weight is added is equivalent to
changing the acceleration of gravity, which is also equivalent to
applying a constant acceleration.  The deflection will be a function
of the free period; the greater the period the greater the
deflection.  This assumes that there is no friction at the hinge.  To
test various hinges, one would want a very long period
pendulum.  Then a very small weight should cause a known, specific
deflection.  If there is less deflection, then the cause must be friction.

Usually the term sensitivity relates to the electronic output per
unit of motion, measured as displacement or velocity or acceleration
at a given period.

Cheers,
John


Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 16:29:55 -0700 Yes, there is this very large OLD geospace ( Texas I think ) Seismometer that weighs about 500 lbs avodupoise and you test it by taking a known weight ( 1gm ( metric ) ball bearing ) on a string ( dental floss ). using the string you place the weight upon an adjusting screw mounted to the suspended mass then let it rest till all motion ceases then you yank on the string to instantly remove the small weight. This will simulate an impules of a one way acceleration relating directly to the mass removed. You can then look at the trace and see if free period and damping and sensitivity are ok or adjustments or repairs are necessary. This barontosaurous of geophones is actually quite good but need a special home underground or dampness ( exposure ) will destroy it. It is also extremely difficult to move around being 500lbs. sort of like one of those mystical magical squeegee sharpening machines you boss sometimes wants you to find. If it happens to weigh 500 lbs and is bolted down it might take all day to deal with. I have the best way to simulate this with smaller geophones is to pulse it with a battery limiting the current flow ( resistor ) to whatever produces 100 or so microvolts across the geophone. You just need to be consistant with the chosen form of testing. If you really want to get it ringing with minimal damping zap ( momentarily not continuous ) it with a 9V battery. ( magnet spring type only ) Regards; geoff ----- Original Message ----- From: "meredith lamb" To: Sent: Wednesday, October 31, 2007 2:57 PM Subject: Mass deflection weight test > Hi all, > > Quite some time back, their was a reference (text) regarding a rough > "deflection" test; > where a small item (feather or something similar), was placed upon the mass > of a > vertical seismometer, and that displacement was a rough measure of (I think) > of its > crude sensitivity? > > Anybody have a knowledge of such; or a exact PSN email reference...or their > experiences? > > Thanks, Meredith Lamb > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 16:33:14 -0700 CRC handbook from the library or possibly arrl. ----- Original Message ----- From: "John Lahr" To: Sent: Thursday, November 01, 2007 12:49 PM Subject: Re: Mass deflection weight test > That's a good idea. Is there a good wire table on line that can be used? > > John > > At 12:03 PM 11/1/2007, you wrote: >>In a message dated 01/11/2007, johnjan@........ writes: >>There are two issues involved. One is the absolute deflection due to >>adding a weight and the other is the electronic response, once some >>motion sensor has been applied. >> >>Hi John, >> >> I find it easier to cut a measured length of Copper wire and >> bend it so that it gives a three point contact - a small U loop and >> a larger U loop at right angles to it. You can look up the weight >> either in wire tables or by the diameter for that gauge and the >> density of Copper. >> >> Regards, >> >> Chris > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "Jerry Payton" gpayton880@....... Date: Thu, 1 Nov 2007 18:48:55 -0500 http://www.powerstream.com/Wire_Size.htm http://en.wikipedia.org/wiki/American_wire_gauge These site may help also. Regards, Jerry ----- Original Message ----- From: Geoff To: psn-l@.............. Sent: Thursday, November 01, 2007 6:33 PM Subject: Re: Mass deflection weight test CRC handbook from the library or possibly arrl. ----- Original Message ----- From: "John Lahr" To: Sent: Thursday, November 01, 2007 12:49 PM Subject: Re: Mass deflection weight test > That's a good idea. Is there a good wire table on line that can be used? > > John > > At 12:03 PM 11/1/2007, you wrote: >>In a message dated 01/11/2007, johnjan@........ writes: >>There are two issues involved. One is the absolute deflection due to >>adding a weight and the other is the electronic response, once some >>motion sensor has been applied. >> >>Hi John, >> >> I find it easier to cut a measured length of Copper wire and >> bend it so that it gives a three point contact - a small U loop and >> a larger U loop at right angles to it. You can look up the weight >> either in wire tables or by the diameter for that gauge and the >> density of Copper. >> >> Regards, >> >> Chris > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
http://www.powerstream.= com/Wire_Size.htm
 
http://en.wikip= edia.org/wiki/American_wire_gauge
 
These site may help also.
 
Regards,
Jerry
 
 
----- Original Message -----=20
From: Geoff
Sent: Thursday, November 01, 2007 6:33 PM
Subject: Re: Mass deflection weight test

CRC handbook from the library or possibly = arrl.

-----=20 Original Message -----
From: "John Lahr" <johnjan@........>
To: <psn-l@..............>
Sent= :=20 Thursday, November 01, 2007 12:49 PM
Subject: Re: Mass deflection = weight=20 test


> That's a good idea.  Is there a good wire = table on=20 line that can be used?
>
> John
>
> At 12:03 = PM=20 11/1/2007, you wrote:
>>In a message dated 01/11/2007, johnjan@........ = writes:
>>There are=20 two issues involved.  One is the absolute deflection due=20 to
>>adding a weight and the other is the electronic response, = once=20 some
>>motion sensor has been = applied.
>>
>>Hi=20 John,
>>
>>     I find it easier = to cut a=20 measured length of Copper wire and
>> bend it so that it gives = a three=20 point contact - a small U loop and
>> a larger U loop at right = angles=20 to it. You can look up the weight
>> either in wire tables or = by the=20 diameter for that gauge and the
>> density of=20 Copper.
>>
>>    =20 Regards,
>>
>>     Chris
> =
>=20
> = __________________________________________________________
>=20
> Public Seismic Network Mailing List (PSN-L)
>
> To = leave=20 this list email PSN-L-REQUEST@............... with=20
> the body of the message (first line only): unsubscribe
> = See http://www.seismicnet.co= m/maillist.html=20 for more=20 information.
>
_________________________________________________= _________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Thu, 1 Nov 2007 19:50:44 EDT In a message dated 01/11/2007, gmvoeth@........... writes: I have the best way to simulate this with smaller geophones is to pulse it with a battery limiting the current flow ( resistor ) to whatever produces 100 or so microvolts across the geophone. Hi Geoff, One other way to do it is to use a capacitor with a resistor in series. You charge up the capacitor to a known voltage and simply short it across the geophone, seismometer etc. This supplies a known charge I x T to the system and the resistor damps any oscillations. Regards, Chris Chapman
In a message dated 01/11/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have=20 the best way to simulate this with smaller geophones is to pulse it with a= =20 battery limiting
the current flow ( resistor ) to whatever produces 100= or=20 so microvolts across the geophone.
Hi Geoff,
 
    One other way to do it is to use a capacitor wi= th a=20 resistor in series. You charge up the capacitor to a known voltage and simpl= y=20 short it across the geophone, seismometer etc. This supplies a known charge=20= I x=20 T to the system and the resistor damps any oscillations. 
 
    Regards,
 
    Chris Chapman
Subject: Re: Mass deflection weight test From: Mark Robinson mark.robinson@............... Date: Fri, 02 Nov 2007 13:34:18 +1300 ChrisAtUpw@....... wrote: > In a message dated 01/11/2007, johnjan@........ writes: > > There are two issues involved. One is the absolute deflection due to > adding a weight and the other is the electronic response, once some > motion sensor has been applied. > I find it easier to cut a measured length of Copper wire and bend it > so that it gives a three point contact - a small U loop and a larger U > loop at right angles to it. You can look up the weight either in wire > tables or by the diameter for that gauge and the density of Copper. Pharmacists usually have a good accurate scale and will weigh things for me if I provide them with some conversation which goes beyond their daily fare of pills and potions. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Thu, 1 Nov 2007 22:13:54 EDT In a message dated 01/11/2007, johnjan@........ writes: That's a good idea. Is there a good wire table on line that can be used? > I find it easier to cut a measured length of Copper wire and > bend it so that it gives a three point contact - a small U loop and > a larger U loop at right angles to it. You can look up the weight > either in wire tables or by the diameter for that gauge and the > density of Copper. Hi John, The density of Copper is 8.933 gm / ml. A wire table is at _http://en.wikipedia.org/wiki/American_wire_gauge_ (http://en.wikipedia.org/wiki/American_wire_gauge) Regards, Chris Chapman
In a message dated 01/11/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>That's a=20 good idea.  Is there a good wire table on line that can be=20 used?

>     I find it easier to cut a measured le= ngth=20 of Copper wire and
> bend it so that it gives a three point contact= - a=20 small U loop and
> a larger U loop at right angles to it. You can l= ook=20 up the weight
> either in wire tables or by the diameter for that g= auge=20 and the
> density of Copper.
Hi John,
 
    The density of Copper is 8.933 gm / ml.
 
    A wire table is at http://en.wikipedi= a.org/wiki/American_wire_gauge
 
    Regards,
 
    Chris Chapman
Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 22:45:15 -0700 Hello Chris; Affirmative, I like that idea. I just found while playing with different configurations what I thought to be a bad geophone. Nothing I would do would get me a good signal from the geophone. After a couple days of considering digging it up I decided to run the signal straight through from the geophone to the A/D converter. I found there to be in the ground a high frequency > 10 Hz that was overdriving my preamplifier essentially "jamming" the amplifier. I solved this problem simply by filtering harshly with a LPF at about 3 seconds 0.3333... Hz. This will allow me to equalize the signal down to this freq. Conquering the noise also has allowed me to achieve a stable baseline something I have been fretting over the past several years :-( Now I have at a gain of 10,000 and down to DC the ability to see signals between DC and 3 or 4 Hz. If I can ever get back to playing around with that positive feedback arrangement I will let you know what happens. At the moment I had to go back to using the Diff amp to solve the noise problem and get back online. I cant tell you how terribly noisy my location is. With a gain of only about X1000 the geophone was putting out a human artifact that drove the amplifier way beyond its limits. When I put the N=4 LPF with 2.0 Hz Fc The noise was greatly reduced indicating it was above that. When A high freq does this all other signals become distorted or so I found. It seems solving the noise makes everything behave in a more predictable fashion. That was how i spent Halloween between the amplifier and monster shows on tv. Hope you had a nicer holiday. One Other Thing, I have found there to be a common mode capacitance between the shield and wires to the geophone of about 6.74 e-9 farads and would like to hear your comments about proper grounding to the amplifier as it relates to this common mode figure. By common mode i mean if you short the two geophone wires together then measure between the two wires and the shield between the geophone and the house this 6.74nf is what i get after subtracting maybe 0.04nf of meter ( DMM ) capacitance. I know this is important but have no idea the proper way to deal with it. The geophone cable is about 35 to 40 feet long and is 100% shielded with copper foil and infused wuth what looks to be silicone grease for underground buriel. Regards; geoff ----- Original Message ----- From: To: Sent: Thursday, November 01, 2007 4:50 PM Subject: Re: Mass deflection weight test > > In a message dated 01/11/2007, gmvoeth@........... writes: > > I have the best way to simulate this with smaller geophones is to pulse it > with a battery limiting > the current flow ( resistor ) to whatever produces 100 or so microvolts > across the geophone. > > > > Hi Geoff, > > One other way to do it is to use a capacitor with a resistor in series. > You charge up the capacitor to a known voltage and simply short it across the > geophone, seismometer etc. This supplies a known charge I x T to the system > and the resistor damps any oscillations. > > Regards, > > Chris Chapman > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 23:03:18 -0700 Hello Cruel World; My geophone here at GVA is buried underground so I can do no direct testing. It seems that Chris's Capacitor test may very well one of the best. But i would not use any resistors I would simply short it across the geophone as it sits attached to the amplifier, let the circuit do whatever so you can see its normal response to the stimulus. Here I am plagued by static electricity so I would be careful there. You might damage the amplifier or geophone insulation if you present somehow 100,000V static charge instead of only the 1 or so volts desired depending upon the value of the capacitor. I used to work in FAT on DEC ( Digital Equipment Corp now owned by HP ) Digital Data comm boards (1980s :-( ) and would see field service people get returns that had a dendrite of chips fail due to static discharges like lightning. Not just the input chip but fanning out several chips deep. I see these computers with big plexiglass holes in the sides. It seems to me any kind of EMP like lightning can get in there and do some damage. You really need a faraday shield to protect anything today. regards geoff ----- Original Message ----- From: "Mark Robinson" To: Sent: Thursday, November 01, 2007 5:34 PM Subject: Re: Mass deflection weight test > ChrisAtUpw@....... wrote: >> In a message dated 01/11/2007, johnjan@........ writes: >> >> There are two issues involved. One is the absolute deflection due to >> adding a weight and the other is the electronic response, once some >> motion sensor has been applied. >> I find it easier to cut a measured length of Copper wire and bend it >> so that it gives a three point contact - a small U loop and a larger U >> loop at right angles to it. You can look up the weight either in wire >> tables or by the diameter for that gauge and the density of Copper. > > Pharmacists usually have a good accurate scale and will weigh things for me if > I provide them with some conversation which goes beyond their daily fare of > pills and potions. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Signal To Noise Ratio From: Bob Hancock carpediem1@......... Date: Sat, 03 Nov 2007 13:16:50 -0700 When downloading events through IRIS =AD Wilber II, I noticed that they liste= d the signal to noise ratio. Most of the time the number was =AD1; however, there were other numbers listed. I have some questions and hopefully someone can answer them. 1. What is the significance of signal to noise ratio when looking at earthquakes? 2. How is signal to noise ratio computed? 3. What are the ideal numbers to look for and at what point does the data become unusable? Thanks Bob Hancock Signal To Noise Ratio When = downloading events through IRIS – Wilber II, I noticed that they liste= d the signal to noise ratio.  Most of the time the number was –1;= however, there were other numbers listed.  I have some questions and h= opefully someone can answer them.


1.  What is the significance of signal to noise ratio when looking at = earthquakes?

2.  How is signal to noise ratio computed?

3.  What are the ideal numbers to look for and at what point does the = data become unusable?

Thanks

Bob Hancock

 Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Sat, 3 Nov 2007 16:26:09 -0700 All I know is signal to noise ratio is one of the most important characteristics of any sensor. You want the sensor noise and electronic noise to reside lower than the ground noise in the most quiet of areas. I think a supercooled sensor is the only way to do this unless the natural noises are great. Pioneer had this thing called a supertuner which would let me see radio waves bouncing off ion trails left by meteors. Built a 3 element yagi-uda adjustable so it could be tuned anywhere in the FM band and between that antenna and the supertuner I had great fun listening into FM stations over 1000 miles away when certain meteors streaked below about 45deg elevation normal to my location. I think the supertuner used the then newly built gallium arsinide front ends that were the best signal to noise ratio of the time 1990 ?? That is the kind of hardware we need too. I think there exists the possibility of somehow demodulating the noise to witness a general increase in its overall amplitude to receive signals lower then the noise yet since it sums with the noise will present itself as an increase in the noise but you can not see the actual signal doing this. They do this in signal analysis by integrating signals over long periods of time like 24 hours just to look for one kind of signal or other. It seems you can see signals up to -40Db below the background??? To me that is a level 0.01 the actual noise itself. ??? Wish i knew more but when the USA lables one mentally ill the relm of meaningful technical research and development can only be learned through the process of educational/informational osmosis. :-) geoff ----- Original Message ----- From: "Bob Hancock" To: "PSN" Sent: Saturday, November 03, 2007 1:16 PM Subject: Signal To Noise Ratio When downloading events through IRIS ­ Wilber II, I noticed that they listed the signal to noise ratio. Most of the time the number was ­1; however, there were other numbers listed. I have some questions and hopefully someone can answer them. 1. What is the significance of signal to noise ratio when looking at earthquakes? 2. How is signal to noise ratio computed? 3. What are the ideal numbers to look for and at what point does the data become unusable? Thanks Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Sat, 3 Nov 2007 16:50:57 -0700 Hello Bob; Have you ever heard of a low noise GaAs op amp that is designed to work like a op177G (typical opamp) or ?? Signal to noise ratio should be easily found in google I think it simply is like Expectided MDL signal power / Ubiquitous Noise Power The higher the ratio the better the whatever. Possibly expressed in db. For power thats 10Log(Sig/Noi). The noise would be the reference point. If you can get a 120db (coopers) I think youd be in fat city. The higher the overall s/n ratio the smaller signals they can see. Like someone sneezing next door. :-) geoff ----- Original Message ----- From: "Bob Hancock" To: "PSN" Sent: Saturday, November 03, 2007 1:16 PM Subject: Signal To Noise Ratio When downloading events through IRIS ­ Wilber II, I noticed that they listed the signal to noise ratio. Most of the time the number was ­1; however, there were other numbers listed. I have some questions and hopefully someone can answer them. 1. What is the significance of signal to noise ratio when looking at earthquakes? 2. How is signal to noise ratio computed? 3. What are the ideal numbers to look for and at what point does the data become unusable? Thanks Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: Bob Hancock carpediem1@......... Date: Sat, 03 Nov 2007 17:06:31 -0700 Hi Geoff - Unfortunately, my knowledge of electronics is less than stellar. I am working at understanding concepts of seismology. As for electronics.....well, I'll leave that for someone else. I was hoping to find an answer that would allow me to apply the SNR numbers I see to the practical side of seismology. I understand the simple concept of an amplifier (boosting a signal), but unfortunately, I have no working knowledge of their innards or how the individual parts work by themselves and in concert with each other. Bob H On 11/3/07 4:50 PM, "Geoff" wrote: > Hello Bob; >=20 > Have you ever heard of a low noise > GaAs op amp that is designed to work > like a op177G (typical opamp) or ?? >=20 > Signal to noise ratio should be easily found > in google I think it simply is like > Expectided MDL signal power / Ubiquitous Noise Power > The higher the ratio the better the whatever. > Possibly expressed in db. > For power thats 10Log(Sig/Noi). > The noise would be the reference point. > If you can get a 120db (coopers) > I think youd be in fat city. > The higher the overall s/n ratio > the smaller signals they can see. > Like someone sneezing next door. >=20 > :-) > geoff >=20 > ----- Original Message ----- > From: "Bob Hancock" > To: "PSN" > Sent: Saturday, November 03, 2007 1:16 PM > Subject: Signal To Noise Ratio >=20 >=20 > When downloading events through IRIS =AD Wilber II, I noticed that they lis= ted > the signal to noise ratio. Most of the time the number was =AD1; however, > there were other numbers listed. I have some questions and hopefully > someone can answer them. >=20 >=20 > 1. What is the significance of signal to noise ratio when looking at > earthquakes? >=20 > 2. How is signal to noise ratio computed? >=20 > 3. What are the ideal numbers to look for and at what point does the dat= a > become unusable? >=20 > Thanks >=20 > Bob Hancock >=20 >=20 >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: Brad Douglas rez@.................. Date: Sat, 03 Nov 2007 17:48:29 -0700 On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote: > Hello Bob; > > Have you ever heard of a low noise > GaAs op amp that is designed to work > like a op177G (typical opamp) or ?? GaAs FETs go that low in frequency and still yield gain and stability? Lowest I've ever done is 144MHz and that was straining the chip, yielding decreased gain (but still higher than any non-GaAs FET). If my understanding is correct, GaAs is "saturated" above 2GHz, making them ideal for microwave LNAs. Or have I entirely missed the point? :-) > Signal to noise ratio should be easily found > in google I think it simply is like > Expectided MDL signal power / Ubiquitous Noise Power > The higher the ratio the better the whatever. > Possibly expressed in db. > For power thats 10Log(Sig/Noi). That's mostly accurate: http://en.wikipedia.org/wiki/Signal-to-noise_ratio -- 73, de Brad KB8UYR/6 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Mag 5.8 earthquake in Antarctica From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 04 Nov 2007 21:04:12 +0000 Hi all There was an unusual earthquake in Antartica at 20:35, the earthquake was mb5.8 (early resaults) and the depth is 40 km according to the same early resaults. This is quite unusual, since there isn't any known faults there, I think. This might be volcano related, but I don't have any way to confirm it. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Tue, 6 Nov 2007 02:26:21 -0700 Interesting Mr. Brad Douglas; Im not sure about any of this but it would be nice to understand what is in the front end of the first PIONEER SUPERTUNERS. I think there are very low noise devices out there but it would be useless to use them in any high noise environment like ShortWave radio. All one really needs is to keep the combined circuit noise below the ambient noise or you will have a hard time seeing the those signals riding near the natural grass. The astronomers will supercool their preamps to eliminate noise and do any broadband shifting right in the front end. I think i would like to have an Astronomical expert making the electronics for my geophone but fear I would not be able to afford the liquid helium to keep it in operation. :-) Regards; geoff ----- Original Message ----- From: "Brad Douglas" To: Sent: Saturday, November 03, 2007 5:48 PM Subject: Re: Signal To Noise Ratio > On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote: >> Hello Bob; >> >> Have you ever heard of a low noise >> GaAs op amp that is designed to work >> like a op177G (typical opamp) or ?? > > GaAs FETs go that low in frequency and still yield gain and stability? > Lowest I've ever done is 144MHz and that was straining the chip, > yielding decreased gain (but still higher than any non-GaAs FET). If my > understanding is correct, GaAs is "saturated" above 2GHz, making them > ideal for microwave LNAs. > > Or have I entirely missed the point? :-) > >> Signal to noise ratio should be easily found >> in google I think it simply is like >> Expectided MDL signal power / Ubiquitous Noise Power >> The higher the ratio the better the whatever. >> Possibly expressed in db. >> For power thats 10Log(Sig/Noi). > > That's mostly accurate: > http://en.wikipedia.org/wiki/Signal-to-noise_ratio > > > -- > 73, de Brad KB8UYR/6 > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Tue, 6 Nov 2007 02:44:42 -0700 Hello Bob; I guess I am no scientist because the basic idea seems so simple to me that the signal to noise ratio can be somewhat arbitrary in your selection of reference points. You pick a signal level of interest and make sure your S/N ratio is such you will actually see the signal of interest. Any signal with like 6dbv X2 above the noise should be visible. One that is 120db is a million times the noise. It all depends upon what noise you mean and to me that is overall "S" noise. White Noise. Like on an "S" meter. As any bubblehead should know ( Sub-Sailor ) S/N is one of the sinle most important facets of any sensor device. I am amazed that an NMR machine can rattle a mole of atoms in a strong magnetic gradient and listen to them ring With various frequencies in response. They must have a receiver unlike anything I am familiar with. I would start by looking at the USGS noise levels then figure out what S/N ratio needs to be before designing a serious device. The place i live in here is so terribly noisy I need to filter right at the preamp to keep my electronics from being jammed by higher vehicular frequencies. It probably would do me little good to invest in high class low noise amplifiers at my current location. The overall noise of your system needs to be lower than the grass. To the point of diminishing returns. The grass being the noise in the ground at whatever bandwidth during a quiet sunday morning like 3am local time. Most people do not build their own devices and do not concern themselves with this thought. There are many types of noise but the only one of interest is the overall results. I cant wait until Universal Entropy Reaches Maximum That will be the quietist time of all. Regards geoff ----- Original Message ----- From: "Bob Hancock" To: Sent: Saturday, November 03, 2007 5:06 PM Subject: Re: Signal To Noise Ratio Hi Geoff - Unfortunately, my knowledge of electronics is less than stellar. I am working at understanding concepts of seismology. As for electronics.....well, I'll leave that for someone else. I was hoping to find an answer that would allow me to apply the SNR numbers I see to the practical side of seismology. I understand the simple concept of an amplifier (boosting a signal), but unfortunately, I have no working knowledge of their innards or how the individual parts work by themselves and in concert with each other. Bob H On 11/3/07 4:50 PM, "Geoff" wrote: > Hello Bob; > > Have you ever heard of a low noise > GaAs op amp that is designed to work > like a op177G (typical opamp) or ?? > > Signal to noise ratio should be easily found > in google I think it simply is like > Expectided MDL signal power / Ubiquitous Noise Power > The higher the ratio the better the whatever. > Possibly expressed in db. > For power thats 10Log(Sig/Noi). > The noise would be the reference point. > If you can get a 120db (coopers) > I think youd be in fat city. > The higher the overall s/n ratio > the smaller signals they can see. > Like someone sneezing next door. > > :-) > geoff > > ----- Original Message ----- > From: "Bob Hancock" > To: "PSN" > Sent: Saturday, November 03, 2007 1:16 PM > Subject: Signal To Noise Ratio > > > When downloading events through IRIS ­ Wilber II, I noticed that they listed > the signal to noise ratio. Most of the time the number was ­1; however, > there were other numbers listed. I have some questions and hopefully > someone can answer them. > > > 1. What is the significance of signal to noise ratio when looking at > earthquakes? > > 2. How is signal to noise ratio computed? > > 3. What are the ideal numbers to look for and at what point does the data > become unusable? > > Thanks > > Bob Hancock > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Unknown event From: tchannel1@............ Date: Tue, 6 Nov 2007 11:19:29 -0700 Hi Folks, I got the 5.4 Guerrero, Mexico, here in Boise, at about = 06:42, It was followed be another one, at about 06:52 UTC. I can't = identify this one? =20 Thanks, Ted
Hi Folks,  I got the 5.4 Guerrero, = Mexico,=20 here in Boise, at about 06:42,  It was followed be another one, at = about=20 06:52 UTC.   I can't identify this one? 
 
Thanks, Ted
Subject: Re: Unknown event From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Tue, 06 Nov 2007 18:31:27 +0000 Hi There was a ML4.3 earthquake at 06:41 in SERAM, INDONESIA (sorry for the caps). Maybe it was that one ? More details. http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D69262 Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Guerrero Mexico 5.4M From: tchannel1@............ Date: Tue, 6 Nov 2007 13:48:56 -0700 Hi Folks, I now think my unidentified event was just the remainder of = the 5.4, not a separate event. Thanks, Ted
Hi Folks,  I now think my = unidentified event=20 was just the remainder of the 5.4,  not a separate = event.  =20 Thanks,
Ted
Subject: noise and seismometer performance From: Randall Peters PETERS_RD@.......... Date: Wed, 07 Nov 2007 08:38:31 -0500 Various of the latest list-serve comments are concerned with SNR of instruments, so I've decided to describe a few of the things I've learned after about two decades of intense research on the non-ideal properties of mechanical oscillators. To the extent that linear approximations are meaningful (not really true at low frequencies and small amplitudes), the theoretical description of a seismometer's performance is straightforward, and treated in the paper I wrote, titled "Seismometer performance based on a simple theory of instrument-generated noise equivalent power", online at http://physics.mercer.edu/hpage/inep/inep.html If you look at this paper, pay close attention to the difference between conventional instruments that output the time derivative of mass position (velocity) and the VolksMeter (position). Because every seismometer (as Einstein well understood, because of inertia) responds only to acceleration (tilt being a special case), the conventional instruments measure the 'jerk' of the earth, whereas the VolksMeter measures its acceleration. The two systems offer synergetic possibilities--jerk sensors better for the high frequency range and acceleration sensors better for the low frequency range. Some of the recent comments are concerned wtih noise equivalent power generated by electronic devices. Such noise is inevitable and temperature plays a dominant role in the electronics. It has been understood for decades from the time of Johnson, and its treatment is straightforward. Insofar as temperature dependence of the mass/spring of a seismometer is concerned, this is an entirely different issue. A common calculation of the Brownian motion of the seismic mass (which suggests a simple advanatage to operating at lower temperatures) is meaningless. The equation employed is based on the equipartition theorem, which does not apply because the number of 'degrees of freedom' in the non-ideal spring is much greater than the number two that is assumed; i.e., one term for the potential energy and one term for the kinetic energy (each contribution one-half kT of thermal energy), naively assuming a harmonic potential (based on Hooke's law which is known to be not-obeyed). For those interested in some of the foundation physics responsible for seismometer difficulties due to mesoanelastic complexity, I wrote the article "Anharmonic Oscillator" for the the 10th Ed. of McGraw Hill's Encyclopedia of Science and Technology. Typing into Google the expression damping anharmonicity -- will return the Access Science quote of the first part of this article. To read the whole article you will have to either (i) pay something to McGraw Hill or (ii) contact me and I will return a copy by email attachment. Internal friction is intimately related to the instrument-generated noise equivalent power and readers may find interesting the following paper: "Harmonic oscillator potential to describe internal dissipation", online at http://arxiv.org/html/physics/0307016 Seismometer theory is hard enough to understand, even when based on linear (overly idealized) approximations. Even the professional seismologists, along with myself, have been guilty of erroneous assumptions. I believe, after more than a decade of trying to acquire self-consistency in at least the linear descriptions--that I'm getting close to a first-order approximate description that is valid for the first-cut of instrument design. A full understanding of the real-world properties of seismometers is truly impossible at this point in time, because we don't understand internal friction from first principles. In the article that I wrote, titled "Friction at the mesoscale", Contemporary Physics vol. 45, no. 6, pp. 475-490 (2004), I included a quote from a Nature article (Kessler) that speaks to the matter; i.e., "It is one of the dirty little secrets of physics that while we physicists can tell you a lot about quarks, quasars, and other exotica; there still is no universally accepted explanation of the basic laws of friction". As noted in the paper, I had actually contemplated a title "Friction, friction everywhere but in our understanding". Randall psn-l-digest-request@.............. wrote: > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Signal To Noise Ratio > From: "Geoff" > Date: Tue, 6 Nov 2007 02:26:21 -0700 > > Interesting Mr. Brad Douglas; > > Im not sure about any of this > but it would be nice to understand > what is in the front end of the > first PIONEER SUPERTUNERS. > > I think there are very low noise devices out there > but it would be useless to use them > in any high noise environment like > ShortWave radio. > > All one really needs is to keep the > combined circuit noise below the > ambient noise or you will have > a hard time seeing the those signals > riding near the natural grass. > > The astronomers will supercool > their preamps to eliminate noise and > do any broadband shifting right in > the front end. > > I think i would like to have > an Astronomical expert making the > electronics for my geophone > but fear I would not be able to > afford the liquid helium to > keep it in operation. > :-) > > Regards; > geoff > ----- Original Message ----- > From: "Brad Douglas" > To: > Sent: Saturday, November 03, 2007 5:48 PM > Subject: Re: Signal To Noise Ratio > > > On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote: > >> Hello Bob; > >> > >> Have you ever heard of a low noise > >> GaAs op amp that is designed to work > >> like a op177G (typical opamp) or ?? > > > > GaAs FETs go that low in frequency and still yield gain and stability? > > Lowest I've ever done is 144MHz and that was straining the chip, > > yielding decreased gain (but still higher than any non-GaAs FET). If my > > understanding is correct, GaAs is "saturated" above 2GHz, making them > > ideal for microwave LNAs. > > > > Or have I entirely missed the point? :-) > > > >> Signal to noise ratio should be easily found > >> in google I think it simply is like > >> Expectided MDL signal power / Ubiquitous Noise Power > >> The higher the ratio the better the whatever. > >> Possibly expressed in db. > >> For power thats 10Log(Sig/Noi). > > > > That's mostly accurate: > > http://en.wikipedia.org/wiki/Signal-to-noise_ratio > > > > > > -- > > 73, de Brad KB8UYR/6 > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 2 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Signal To Noise Ratio > From: "Geoff" > Date: Tue, 6 Nov 2007 02:44:42 -0700 > > Hello Bob; > > I guess I am no scientist because the basic > idea seems so simple to me that the signal to noise > ratio can be somewhat arbitrary in your selection > of reference points. > > You pick a signal level of interest > and make sure your S/N ratio is such > you will actually see the signal of interest. > > Any signal with like 6dbv X2 above the noise > should be visible. One that is 120db > is a million times the noise. > > It all depends upon what noise you mean > and to me that is overall "S" noise. > White Noise. Like on an "S" meter. > > As any bubblehead should know ( Sub-Sailor ) > S/N is one of the sinle most important facets > of any sensor device. > > I am amazed that an NMR machine can > rattle a mole of atoms in a strong > magnetic gradient and listen > to them ring With various frequencies > in response. > > They must have a receiver unlike anything > I am familiar with. > > I would start by looking at the USGS noise levels > then figure out what S/N ratio needs to be > before designing a serious device. > The place i live in here is so terribly > noisy I need to filter right at the > preamp to keep my electronics from > being jammed by higher vehicular frequencies. > > It probably would do me little good > to invest in high class low noise > amplifiers at my current location. > > The overall noise of your system > needs to be lower than the grass. > To the point of diminishing returns. > The grass being the noise in the ground > at whatever bandwidth during a quiet > sunday morning like 3am local time. > > Most people do not build their own > devices and do not concern themselves > with this thought. > There are many types of noise but the only > one of interest is the overall results. > I cant wait until Universal Entropy Reaches Maximum > That will be the quietist time of all. > > Regards > geoff > > ----- Original Message ----- > From: "Bob Hancock" > To: > Sent: Saturday, November 03, 2007 5:06 PM > Subject: Re: Signal To Noise Ratio > > Hi Geoff - > > Unfortunately, my knowledge of electronics is less than stellar. I am > working at understanding concepts of seismology. As for > electronics.....well, I'll leave that for someone else. I was hoping to > find an answer that would allow me to apply the SNR numbers I see to the > practical side of seismology. I understand the simple concept of an > amplifier (boosting a signal), but unfortunately, I have no working > knowledge of their innards or how the individual parts work by themselves > and in concert with each other. > > Bob H > > On 11/3/07 4:50 PM, "Geoff" wrote: > > > Hello Bob; > > > > Have you ever heard of a low noise > > GaAs op amp that is designed to work > > like a op177G (typical opamp) or ?? > > > > Signal to noise ratio should be easily found > > in google I think it simply is like > > Expectided MDL signal power / Ubiquitous Noise Power > > The higher the ratio the better the whatever. > > Possibly expressed in db. > > For power thats 10Log(Sig/Noi). > > The noise would be the reference point. > > If you can get a 120db (coopers) > > I think youd be in fat city. > > The higher the overall s/n ratio > > the smaller signals they can see. > > Like someone sneezing next door. > > > > :-) > > geoff > > > > ----- Original Message ----- > > From: "Bob Hancock" > > To: "PSN" > > Sent: Saturday, November 03, 2007 1:16 PM > > Subject: Signal To Noise Ratio > > > > > > When downloading events through IRIS ­ Wilber II, I noticed that they listed > > the signal to noise ratio. Most of the time the number was ­1; however, > > there were other numbers listed. I have some questions and hopefully > > someone can answer them. > > > > > > 1. What is the significance of signal to noise ratio when looking at > > earthquakes? > > > > 2. How is signal to noise ratio computed? > > > > 3. What are the ideal numbers to look for and at what point does the data > > become unusable? > > > > Thanks > > > > Bob Hancock > > > > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 3 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Unknown event > From: > Date: Tue, 6 Nov 2007 11:19:29 -0700 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0007_01C82066.E5EE6CA0 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > Hi Folks, I got the 5.4 Guerrero, Mexico, here in Boise, at about = > 06:42, It was followed be another one, at about 06:52 UTC. I can't = > identify this one? =20 > > Thanks, Ted > ------=_NextPart_000_0007_01C82066.E5EE6CA0 > Content-Type: text/html; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Diso-8859-1"> > > > > >
Hi Folks,  I got the 5.4 Guerrero, = > Mexico,=20 > here in Boise, at about 06:42,  It was followed be another one, at = > about=20 > 06:52 UTC.   I can't identify this one? 
>
 
>
Thanks, Ted
> > ------=_NextPart_000_0007_01C82066.E5EE6CA0-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 4 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Unknown event > From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= > Date: Tue, 06 Nov 2007 18:31:27 +0000 > > Hi > > There was a ML4.3 earthquake at 06:41 in SERAM, INDONESIA (sorry for the > caps). Maybe it was that one ? > > More details. > > http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D69262 > > Regards. > --=20 > J=F3n Fr=EDmann > http://www.jonfr.com > http://earthquakes.jonfr.com > http://www.net303.net > http://www.mobile-coverage.com/ > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 5 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Guerrero Mexico 5.4M > From: > Date: Tue, 6 Nov 2007 13:48:56 -0700 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0005_01C8207B.C6AAFCE0 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > Hi Folks, I now think my unidentified event was just the remainder of = > the 5.4, not a separate event. Thanks, > Ted > ------=_NextPart_000_0005_01C8207B.C6AAFCE0 > Content-Type: text/html; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Diso-8859-1"> > > > > >
Hi Folks,  I now think my = > unidentified event=20 > was just the remainder of the 5.4,  not a separate = > event.  =20 > Thanks,
>
Ted
> > ------=_NextPart_000_0005_01C8207B.C6AAFCE0-- > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-DIGEST-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. Various of the latest list-serve comments are concerned with SNR of instruments, so I've decided to describe a few of the things I've learned after about two decades of intense research on the non-ideal properties of mechanical oscillators.
    To the extent that linear approximations are meaningful (not really true at low frequencies and small
amplitudes), the theoretical description of a seismometer's performance is straightforward, and treated
in the paper I wrote, titled "Seismometer performance based on a simple theory of instrument-generated
noise equivalent power", online at
http://physics.mercer.edu/hpage/inep/inep.html
  If you look at this paper, pay close attention to the difference between conventional instruments that output the time derivative of mass position (velocity) and the VolksMeter (position).  Because every seismometer (as Einstein well understood, because of inertia) responds only to acceleration (tilt being a special case), the conventional instruments measure the 'jerk' of the earth, whereas the VolksMeter measures its acceleration.  The two systems offer synergetic
possibilities--jerk sensors better for the high frequency range and acceleration sensors better for the low frequency
range.
    Some of the recent comments are concerned wtih noise equivalent power generated by electronic devices.  Such
noise is inevitable and temperature plays a dominant role in the electronics. It has been understood for decades
from the time of Johnson, and its treatment is straightforward.  Insofar as temperature dependence
of the mass/spring of a seismometer is concerned, this is an entirely different issue.  A common calculation of the Brownian motion of the seismic mass (which suggests a simple advanatage to operating at lower temperatures) is
meaningless.  The equation employed is based on the equipartition theorem, which does not apply because the
number of 'degrees of freedom' in the non-ideal spring is much greater than the number two that  is assumed;
i.e., one term for the potential energy and one term for the kinetic energy (each contribution one-half kT of thermal
energy), naively assuming a harmonic potential (based on Hooke's law which is known to be not-obeyed).
    For those interested in some of the foundation physics responsible for seismometer difficulties due to mesoanelastic complexity, I wrote the article "Anharmonic Oscillator" for the the 10th Ed. of McGraw Hill's
Encyclopedia of Science and Technology.  Typing into Google the expression damping anharmonicity -- will return the Access Science quote of the first part of this article.  To read the whole article you will have to either (i) pay something to McGraw Hill or (ii) contact me and I will return a copy by email attachment.
    Internal friction is intimately related to the instrument-generated noise equivalent power and readers may find
interesting the following paper:  "Harmonic oscillator potential to describe internal dissipation", online at
http://arxiv.org/html/physics/0307016
     Seismometer theory is hard enough to understand, even when based on linear (overly idealized) approximations.
Even the professional seismologists, along with myself, have been guilty of erroneous assumptions.  I believe, after
more than a decade of trying to acquire self-consistency in at least the linear descriptions--that I'm getting close
to a first-order approximate description that is valid for the first-cut of instrument design.  A full understanding of the real-world properties of seismometers is truly impossible at this point in time, because we don't
understand internal friction from first principles.  In the article that I wrote, titled
"Friction at the mesoscale",  Contemporary Physics vol. 45, no. 6, pp. 475-490 (2004),
I included a quote from a Nature article (Kessler) that speaks to the matter; i.e., "It is one of the dirty little secrets of physics that while we physicists can tell you a lot about quarks, quasars, and other exotica; there still is no universally
accepted explanation of the basic laws of friction".  As noted in the paper, I had actually contemplated
a title "Friction, friction everywhere but in our understanding".

Randall
 
 

psn-l-digest-request@.............. wrote:

.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 1                                                           |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Signal To Noise Ratio
From:    "Geoff" <gmvoeth@...........>
Date:    Tue, 6 Nov 2007 02:26:21 -0700

Interesting Mr. Brad Douglas;

Im not sure about any of this
but it would be nice to understand
what is in the front end of the
first PIONEER SUPERTUNERS.

I think there are very low noise devices out there
but it would be useless to use them
in any high noise environment like
ShortWave radio.

All one really needs is to keep the
combined circuit noise below the
ambient noise or you will have
a hard time seeing the those signals
riding near the natural grass.

The astronomers will supercool
their preamps to eliminate noise and
do any broadband shifting right in
the front end.

I think i would like to have
an Astronomical expert making the
electronics for my geophone
but fear I would not be able to
afford the liquid helium to
keep it in operation.
:-)

Regards;
geoff
----- Original Message -----
From: "Brad Douglas" <rez@..................>
To: <psn-l@..............>
Sent: Saturday, November 03, 2007 5:48 PM
Subject: Re: Signal To Noise Ratio

> On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote:
>> Hello Bob;
>>
>> Have you ever heard of a low noise
>> GaAs op amp that is designed to work
>> like a op177G (typical opamp) or ??
>
> GaAs FETs go that low in frequency and still yield gain and stability?
> Lowest I've ever done is 144MHz and that was straining the chip,
> yielding decreased gain (but still higher than any non-GaAs FET).  If my
> understanding is correct, GaAs is "saturated" above 2GHz, making them
> ideal for microwave LNAs.
>
> Or have I entirely missed the point? :-)
>
>> Signal to noise ratio should be easily found
>> in google I think it simply is like
>> Expectided MDL signal power / Ubiquitous Noise Power
>> The higher the ratio the better the whatever.
>> Possibly expressed in db.
>> For power thats 10Log(Sig/Noi).
>
> That's mostly accurate:
> http://en.wikipedia.org/wiki/Signal-to-noise_ratio
>
>
> --
> 73, de Brad KB8UYR/6 <rez touchofmadness com>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>

.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 2                                                           |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Signal To Noise Ratio
From:    "Geoff" <gmvoeth@...........>
Date:    Tue, 6 Nov 2007 02:44:42 -0700

Hello Bob;

I guess I am no scientist because the basic
idea seems so simple to me that the signal to noise
ratio can be somewhat arbitrary in your selection
of reference points.

You pick a signal level of interest
and make sure your S/N ratio is such
you will actually see the signal of interest.

Any signal with like 6dbv X2 above the noise
should be visible. One that is 120db
is a million times the noise.

It all depends upon what noise you mean
and to me that is overall "S" noise.
White Noise. Like on an "S" meter.

As any bubblehead should know ( Sub-Sailor )
S/N is one of the sinle most important facets
of any sensor device.

I am amazed that an NMR machine can
rattle a mole of atoms in a strong
magnetic gradient and listen
to them ring With various frequencies
in response.

They must have a receiver unlike anything
I am familiar with.

I would start by looking at the USGS noise levels
then figure out what S/N ratio needs to be
before designing a serious device.
The place i live in here is so terribly
noisy I need to filter right at the
preamp to keep my electronics from
being jammed by higher vehicular frequencies.

It probably would do me little good
to invest in high class low noise
amplifiers at my current location.

The overall noise of your system
needs to be lower than the grass.
To the point of diminishing returns.
The grass being the noise in the ground
at whatever bandwidth during a quiet
sunday morning like 3am local time.

Most people do not build their own
devices and do not concern themselves
with this thought.
There are many types of noise but the only
one of interest is the overall results.
I cant wait until Universal Entropy Reaches Maximum
That will be the quietist time of all.

Regards
geoff

----- Original Message -----
From: "Bob Hancock" <carpediem1@.........>
To: <psn-l@..............>
Sent: Saturday, November 03, 2007 5:06 PM
Subject: Re: Signal To Noise Ratio

Hi Geoff -

Unfortunately, my knowledge of electronics is less than stellar.  I am
working at understanding concepts of seismology.  As for
electronics.....well, I'll leave that for someone else.  I was hoping to
find an answer that would allow me to apply the SNR numbers I see to the
practical side of seismology.  I understand the simple concept of an
amplifier (boosting a signal), but unfortunately, I have no working
knowledge of their innards or how the individual parts work by themselves
and in concert with each other.

Bob H

On 11/3/07 4:50 PM, "Geoff" <gmvoeth@...........> wrote:

> Hello Bob;
>
> Have you ever heard of a low noise
> GaAs op amp that is designed to work
> like a op177G (typical opamp) or ??
>
> Signal to noise ratio should be easily found
> in google I think it simply is like
> Expectided MDL signal power / Ubiquitous Noise Power
> The higher the ratio the better the whatever.
> Possibly expressed in db.
> For power thats 10Log(Sig/Noi).
> The noise would be the reference point.
> If you can get a 120db (coopers)
> I think youd be in fat city.
> The higher the overall s/n ratio
> the smaller signals they can see.
> Like someone sneezing next door.
>
> :-)
> geoff
>
> ----- Original Message -----
> From: "Bob Hancock" <carpediem1@.........>
> To: "PSN" <psn-l@..............>
> Sent: Saturday, November 03, 2007 1:16 PM
> Subject: Signal To Noise Ratio
>
>
> When downloading events through IRIS ­ Wilber II, I noticed that they listed
> the signal to noise ratio.  Most of the time the number was ­1; however,
> there were other numbers listed.  I have some questions and hopefully
> someone can answer them.
>
>
> 1.  What is the significance of signal to noise ratio when looking at
> earthquakes?
>
> 2.  How is signal to noise ratio computed?
>
> 3.  What are the ideal numbers to look for and at what point does the data
> become unusable?
>
> Thanks
>
> Bob Hancock
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.

.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 3                                                           |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Unknown event
From:    <tchannel1@............>
Date:    Tue, 6 Nov 2007 11:19:29 -0700

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Hi Folks,  I got the 5.4 Guerrero, Mexico, here in Boise, at about =
06:42,  It was followed be another one, at about 06:52 UTC.   I can't =
identify this one? =20

Thanks, Ted
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<DIV><FONT face=3DArial size=3D2>Hi Folks,&nbsp; I got the 5.4 Guerrero, =
Mexico,=20
here in Boise, at about 06:42,&nbsp; It was followed be another one, at =
about=20
06:52 UTC.&nbsp;&nbsp; I can't identify this one?&nbsp; </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Thanks, Ted</FONT></DIV></BODY></HTML>

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Subject: Re: Unknown event
From:    =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= <jonfr@.........>
Date:    Tue, 06 Nov 2007 18:31:27 +0000

Hi

There was a ML4.3 earthquake at 06:41 in SERAM, INDONESIA (sorry for the
caps). Maybe it was that one ?

More details.

http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D69262

Regards.
--=20
J=F3n Fr=EDmann
http://www.jonfr.com
http://earthquakes.jonfr.com
http://www.net303.net
http://www.mobile-coverage.com/

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Subject: Guerrero Mexico 5.4M
From:    <tchannel1@............>
Date:    Tue, 6 Nov 2007 13:48:56 -0700

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Hi Folks,  I now think my unidentified event was just the remainder of =
the 5.4,  not a separate event.   Thanks,
Ted
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<DIV><FONT face=3DArial size=3D2>Hi Folks,&nbsp; I now think my =
unidentified event=20
was just the remainder of the 5.4,&nbsp; not a separate =
event.&nbsp;&nbsp;=20
Thanks,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Ted</FONT></DIV></BODY></HTML>

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Subject: idea for an axis From: Randall Peters PETERS_RD@.......... Date: Thu, 08 Nov 2007 11:57:49 -0500 Since the VolksMeter uses tungsten carbide to establish the axis (extracted from ball-point pens), I should have thought of the following a long time ago. A key to reducing rolling friction is to work with hard surfaces. Another key to reducing friction in general (if possible) is to reduce the normal force. Both are achievable by hanging a pendulum from a rare earth magnet, using the ferrous property of the tungsten carbide. In a brief experiment this morning I stuck a 1/2 in cylindrical rare earth magnet to the top of a steel door frame and then hung a ball point pen from the magnet. Discovered that the tungsten carbide tip of the pen could support about 100 grams of weight. Of course this arrangement is unsatisfactory for a seismometer because the physical pendulum that results (swinging pen) moves as a spherical pendulum. To get the required planar motion I took the refills of two pens and glued them together. The pair of pen points can support about 200 grams of an inertial mass while constrained to motion in a plane. The quality factor of this oscillator proved to be really high, with the unit swinging in observable free decay for many hundreds of cycles. It is clear then, that the friction is very small indeed, by (i) taking advantage of the hardness of both the magnet and the small tungsten carbide balls; and (ii) because the field gradient of the magnet provides support for much of the mass of the pendulum, so that the normal force is reduced as compared to most other configurations. For you folks who have played with various axis types, what do you think about this? Randall Subject: Re: idea for an axis From: tchannel1@............ Date: Thu, 8 Nov 2007 10:12:50 -0700 Randall, I think this is brilliant, and well worth dinking with, which I think I will do. Thanks, Ted ----- Original Message ----- From: "Randall Peters" To: Sent: Thursday, November 08, 2007 9:57 AM Subject: idea for an axis > Since the VolksMeter uses tungsten carbide to establish the axis > (extracted from > ball-point pens), I should have thought of the following a long time ago. > A key to reducing rolling friction is to work with hard surfaces. > Another key > to reducing friction in general (if possible) is to reduce the normal > force. Both > are achievable by hanging a pendulum from a rare earth magnet, using the > ferrous > property of the tungsten carbide. > In a brief experiment this morning I stuck a 1/2 in cylindrical rare > earth > magnet to the top of a steel door frame and then hung a ball point pen > from the > magnet. Discovered that the tungsten carbide tip of the pen could support > about > 100 grams of weight. Of course this arrangement is unsatisfactory for a > seismometer because the physical pendulum that results (swinging pen) > moves as a > spherical pendulum. > To get the required planar motion I took the refills of two pens and > glued > them together. The pair of pen points can support about 200 grams of an > inertial > mass while constrained to motion in a plane. > The quality factor of this oscillator proved to be really high, with > the unit > swinging in observable free decay for many hundreds of cycles. It is > clear then, > that the friction is very small indeed, by (i) taking advantage of the > hardness of > both the magnet and the small tungsten carbide balls; and (ii) because the > field > gradient of the magnet provides support for much of the mass of the > pendulum, so > that the normal force is reduced as compared to most other configurations. > For you folks who have played with various axis types, what do you > think > about this? > Randall > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: tchannel1@............ Date: Thu, 8 Nov 2007 14:54:20 -0700 Randall, I did this also, and got similar results. With no special effort I just hung a ball point pen, from a nice rare earth magnet, added enough mass to NOT FALL, and pushed the pendulum about 20 degrees. It rocked or circled for 30 mins, and my estimated count of cycles was 2500. I had done other crude pendulums timing, testing hinges and got about 400 cycles, more or less. I have a room full of different sensors, but now I would like to try this concept on a mini-sensor. Someday..... Thanks for the idea. Ted ----- Original Message ----- From: "Randall Peters" To: Sent: Thursday, November 08, 2007 9:57 AM Subject: idea for an axis > Since the VolksMeter uses tungsten carbide to establish the axis > (extracted from > ball-point pens), I should have thought of the following a long time ago. > A key to reducing rolling friction is to work with hard surfaces. > Another key > to reducing friction in general (if possible) is to reduce the normal > force. Both > are achievable by hanging a pendulum from a rare earth magnet, using the > ferrous > property of the tungsten carbide. > In a brief experiment this morning I stuck a 1/2 in cylindrical rare > earth > magnet to the top of a steel door frame and then hung a ball point pen > from the > magnet. Discovered that the tungsten carbide tip of the pen could support > about > 100 grams of weight. Of course this arrangement is unsatisfactory for a > seismometer because the physical pendulum that results (swinging pen) > moves as a > spherical pendulum. > To get the required planar motion I took the refills of two pens and > glued > them together. The pair of pen points can support about 200 grams of an > inertial > mass while constrained to motion in a plane. > The quality factor of this oscillator proved to be really high, with > the unit > swinging in observable free decay for many hundreds of cycles. It is > clear then, > that the friction is very small indeed, by (i) taking advantage of the > hardness of > both the magnet and the small tungsten carbide balls; and (ii) because the > field > gradient of the magnet provides support for much of the mass of the > pendulum, so > that the normal force is reduced as compared to most other configurations. > For you folks who have played with various axis types, what do you > think > about this? > Randall > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: ChrisAtUpw@....... Date: Thu, 8 Nov 2007 18:43:00 EST In a message dated 08/11/2007, PETERS_RD@.......... writes: Since the VolksMeter uses tungsten carbide to establish the axis, I should have thought of the following a long time ago. A key to reducing rolling friction is to work with hard surfaces. Another key to reducing friction in general (if possible) is to reduce the normal force. Both are achievable by hanging a pendulum from a rare earth magnet, using the ferrous property of the tungsten carbide. Hi Randall, Stainless Steel ball bearings are available in a wide range of sizes. _www.smallparts.com_ (http://www.smallparts.com) They are martensitic Chrome steel and are strongly magnetic. SS martensitic rod is also readily available. It might be worth considering mounting the balls in mild steel with a magnet bridge and attaching them to a hardened SS rod. The magnetic flux would then pass from the magnet, through the mild steel to the balls, across the suspension contacts to the circular rod and then through it. I am uncertain whether the strong permanent magnetism which will be induced near the contact point will add to the dynamic loss. The relatively low net load should decrease the loss. It should be quite practicable to extend this to crossed cylinder suspensions. I would expect the magnetic attraction to be greater for the same diameter. The dynamic loss does depend on the bearing type. Previous experiments have shown decreasing loss in the series single wires and foils, crossed wires and foils, ball on a plane, crossed cylinders, rolling wires and foils. These rolling systems use a figure of 8 loops around two circular cylinders. They show ~zero rolling force. Ball on a plane and cylindrical systems may be made self centring by curving the plane / providing a circular support. The choice of system may depend on whether the arm needs to be permanently attached to the support structure. Regards, Chris Chapman
In a message dated 08/11/2007, PETERS_RD@.......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Since=20 the VolksMeter uses tungsten carbide to establish the axis, I should have=20 thought of the following a long time ago.
   A key to reducin= g=20 rolling friction is to work with hard surfaces.  Another key to reduc= ing=20 friction in general (if possible) is to reduce the normal force.  Bot= h=20 are achievable by hanging a pendulum from a rare earth magnet, using the=20 ferrous property of the tungsten carbide.
Hi Randall,
 
    Stainless Steel ball bearings are available in=20= a=20 wide range of sizes. www.smallparts.co= m=20 They are martensitic Chrome steel and are strongly magnetic. SS martensitic=20= rod=20 is also readily available. It might be worth considering mounting the balls=20= in=20 mild steel with a magnet bridge and attaching them to a hardened SS rod. The= =20 magnetic flux would then pass from the magnet, through the mild steel to the= =20 balls, across the suspension contacts to the circular rod and then through=20 it.
    =20
    I am uncertain whether the strong permanent=20 magnetism which will be induced near the contact point will add to the dynam= ic=20 loss. The relatively low net load should decrease the loss.
    It should be quite practicable to extend this t= o=20 crossed cylinder suspensions. I would expect the magnetic attraction to be=20 greater for the same diameter.
 
    The dynamic loss does depend on the bearing typ= e.=20 Previous experiments have shown decreasing loss in the series single wi= res=20 and foils, crossed wires and foils, ball on a plane, crossed cylinders, roll= ing=20 wires and foils. These rolling systems use a figure of 8 loops aro= und=20 two circular cylinders. They show ~zero rolling force. Ball on a plane and=20 cylindrical systems may be made self centring by curving the plane / providi= ng a=20 circular support. The choice of system may depend on whether the arm needs t= o be=20 permanently attached to the support structure.
 
    Regards,
 
    Chris Chapman
 

 
 
Subject: Re: idea for an axis From: "meredith lamb" paleoartifact@......... Date: Thu, 8 Nov 2007 21:37:17 -0700 Dr. Peters and all, Am only adding some further development thoughts here. Some ball point pens could likely be emptied of their contents; a replacement ball bearing could be glued in place, and the empty plastic could contain, say; whatever lead shot the axis ball bearing pivot could handle weight wise. Of course, one could possibly retain the original ball bearing perhaps by cutting off the ink well tube and glueing. Of course the plastic is both the "boom" and the "mass" weight holder in one. One could "entertain" dual pens also for the vertical sensing approach with a suitable spring....the dual ball bearing pivot/axis points should make it quite stable. I suppose its also possible to electrically isolate the contact points of the axis points, and run wires to a bulb somewhere at the base of one of the pens; for light sensing variation output. Of course there is other ways of suing light sensing without using a bulb in one of the pens. Anyway....have tried only one working ball point here. Its a big size, "Gelwriter Rx", I got from a Costco store. It has a screw on head. Even the pocket clip can be easily pulled out of the assembly. The only magnetic item therein was the spring. The clip and the ID ring seem to be stainless. The hand diameter size is noteably larger than the average ball point pens on the U.S. market. Some of the plastic is colored to look like metal. I tried another ball point....but, its ball bearing didn't appear to be even magnetic. Quite some time back, Chris Chapman checked out a variety of ball point pens, and found the ball bearing diameters can vary. Meredith Lamb On Nov 8, 2007 9:57 AM, Randall Peters wrote: > Since the VolksMeter uses tungsten carbide to establish the axis > (extracted from > ball-point pens), I should have thought of the following a long time ago. > A key to reducing rolling friction is to work with hard surfaces. > Another key > to reducing friction in general (if possible) is to reduce the normal > force. Both > are achievable by hanging a pendulum from a rare earth magnet, using the > ferrous > property of the tungsten carbide. > In a brief experiment this morning I stuck a 1/2 in cylindrical rare > earth > magnet to the top of a steel door frame and then hung a ball point pen > from the > magnet. Discovered that the tungsten carbide tip of the pen could support > about > 100 grams of weight. Of course this arrangement is unsatisfactory for a > seismometer because the physical pendulum that results (swinging pen) > moves as a > spherical pendulum. > To get the required planar motion I took the refills of two pens and > glued > them together. The pair of pen points can support about 200 grams of an > inertial > mass while constrained to motion in a plane. > The quality factor of this oscillator proved to be really high, with > the unit > swinging in observable free decay for many hundreds of cycles. It is > clear then, > that the friction is very small indeed, by (i) taking advantage of the > hardness of > both the magnet and the small tungsten carbide balls; and (ii) because the > field > gradient of the magnet provides support for much of the mass of the > pendulum, so > that the normal force is reduced as compared to most other configurations. > For you folks who have played with various axis types, what do you > think > about this? > Randall >
Dr. Peters and all,
 
Am only adding some further development thoughts here.  Some ball point pens
could likely be emptied of their contents; a replacement ball bearing could be
glued in place, and the empty plastic could contain, say; whatever lead shot the
axis ball bearing pivot could handle weight wise.  Of course, one could possibly
retain the original ball bearing perhaps by cutting off the ink well tube and glueing.
Of course the plastic is both the "boom" and the "mass" weight holder in one.
 
One could "entertain" dual pens also for the vertical sensing approach with a
suitable spring....the dual ball bearing pivot/axis points should make it quite stable.
 
I suppose its also possible to electrically isolate the contact points of the
axis points, and run wires to a bulb somewhere at the base of one of the pens;
for light sensing variation output.  Of course there is other ways of suing light
sensing without using a bulb in one of the pens.
 
Anyway....have tried only one working ball point here.  Its a big size, "Gelwriter Rx", I
got from a Costco store.  It has a screw on head.  Even the pocket clip can
be easily pulled out of the assembly.  The only magnetic item therein was the
spring.  The clip and the ID ring seem to be stainless.  The hand diameter
size is noteably larger than the average ball point pens on the U.S. market.
Some of the plastic is colored to look like metal. 
 
I tried another ball point....but, its ball bearing didn't appear to be even magnetic.
 
Quite some time back, Chris Chapman checked out a variety of ball point
pens, and found the ball bearing diameters can vary.   
 
Meredith Lamb 

 
On Nov 8, 2007 9:57 AM, Randall Peters <PETERS_RD@..........> wrote:
Since the VolksMeter uses tungsten carbide to establish the axis (extracted from
ball-point pens), I should have thought of the following a long time ago.
  A key to reducing rolling friction is to work with hard surfaces.  Another key
to reducing friction in general (if possible) is to reduce the normal force.  Both
are achievable by hanging a pendulum from a rare earth magnet, using the ferrous
property of the tungsten carbide.
   In a brief experiment this morning I stuck a 1/2 in cylindrical rare earth
magnet to the top of a steel door frame and then hung a ball point pen from the
magnet.  Discovered that the tungsten carbide tip of the pen could support about
100 grams of weight.  Of course this arrangement is unsatisfactory for a
seismometer because the physical pendulum that results (swinging pen) moves as a
spherical pendulum.
   To get the required planar motion I took the refills of two pens and glued
them together.  The pair of pen points can support about 200 grams of an inertial
mass while constrained to motion in a plane.
   The quality factor of this oscillator proved to be really high, with the unit
swinging in observable free decay for many hundreds of cycles.  It is clear then,
that the friction is very small indeed, by (i) taking advantage of the hardness of
both the magnet and the small tungsten carbide balls; and (ii) because the field
gradient of the magnet provides support for much of the mass of the pendulum, so
that the normal force is reduced as compared to most other configurations.
    For you folks who have played with various axis types, what do you think
about this?
Randall

Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 05:07:40 -0700 DID you clean the ink off the tip before doing this ? ----- Original Message ----- From: To: Sent: Thursday, November 08, 2007 2:54 PM Subject: Re: idea for an axis > Randall, I did this also, and got similar results. With no special effort > I just hung a ball point pen, from a nice rare earth magnet, added enough > mass to NOT FALL, and pushed the pendulum about 20 degrees. It rocked or > circled for 30 mins, and my estimated count of cycles was 2500. I had done > other crude pendulums timing, testing hinges and got about 400 cycles, more > or less. > > I have a room full of different sensors, but now I would like to try this > concept on a mini-sensor. Someday..... > > Thanks for the idea. > Ted > > > > > ----- Original Message ----- > From: "Randall Peters" > To: > Sent: Thursday, November 08, 2007 9:57 AM > Subject: idea for an axis > > >> Since the VolksMeter uses tungsten carbide to establish the axis >> (extracted from >> ball-point pens), I should have thought of the following a long time ago. >> A key to reducing rolling friction is to work with hard surfaces. >> Another key >> to reducing friction in general (if possible) is to reduce the normal >> force. Both >> are achievable by hanging a pendulum from a rare earth magnet, using the >> ferrous >> property of the tungsten carbide. >> In a brief experiment this morning I stuck a 1/2 in cylindrical rare >> earth >> magnet to the top of a steel door frame and then hung a ball point pen >> from the >> magnet. Discovered that the tungsten carbide tip of the pen could support >> about >> 100 grams of weight. Of course this arrangement is unsatisfactory for a >> seismometer because the physical pendulum that results (swinging pen) >> moves as a >> spherical pendulum. >> To get the required planar motion I took the refills of two pens and >> glued >> them together. The pair of pen points can support about 200 grams of an >> inertial >> mass while constrained to motion in a plane. >> The quality factor of this oscillator proved to be really high, with >> the unit >> swinging in observable free decay for many hundreds of cycles. It is >> clear then, >> that the friction is very small indeed, by (i) taking advantage of the >> hardness of >> both the magnet and the small tungsten carbide balls; and (ii) because the >> field >> gradient of the magnet provides support for much of the mass of the >> pendulum, so >> that the normal force is reduced as compared to most other configurations. >> For you folks who have played with various axis types, what do you >> think >> about this? >> Randall >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 05:15:10 -0700 You Will see things like 1mm medium pens and 0.8mm fine I think that may be the diameter of the ball ?? Why Dont People try using these things in a vacuum ? With only Magnetic Damping ?? Put the damper above the sensor so the sensor can get full advantage of the velocity. How in the world can you use such a thing vertically ? ----- Original Message ----- From: "meredith lamb" To: Sent: Thursday, November 08, 2007 9:37 PM Subject: Re: idea for an axis > Dr. Peters and all, > > Am only adding some further development thoughts here. Some ball point pens > could likely be emptied of their contents; a replacement ball bearing could > be > glued in place, and the empty plastic could contain, say; whatever lead shot > the > axis ball bearing pivot could handle weight wise. Of course, one could > possibly > retain the original ball bearing perhaps by cutting off the ink well tube > and glueing. > Of course the plastic is both the "boom" and the "mass" weight holder in > one. > > One could "entertain" dual pens also for the vertical sensing approach with > a > suitable spring....the dual ball bearing pivot/axis points should make it > quite stable. > > I suppose its also possible to electrically isolate the contact points of > the > axis points, and run wires to a bulb somewhere at the base of one of the > pens; > for light sensing variation output. Of course there is other ways of suing > light > sensing without using a bulb in one of the pens. > > Anyway....have tried only one working ball point here. Its a big size, > "Gelwriter Rx", I > got from a Costco store. It has a screw on head. Even the pocket clip can > be easily pulled out of the assembly. The only magnetic item therein was > the > spring. The clip and the ID ring seem to be stainless. The hand diameter > size is noteably larger than the average ball point pens on the U.S. market. > Some of the plastic is colored to look like metal. > > I tried another ball point....but, its ball bearing didn't appear to be even > magnetic. > > Quite some time back, Chris Chapman checked out a variety of ball point > pens, and found the ball bearing diameters can vary. > > Meredith Lamb > > > On Nov 8, 2007 9:57 AM, Randall Peters wrote: > >> Since the VolksMeter uses tungsten carbide to establish the axis >> (extracted from >> ball-point pens), I should have thought of the following a long time ago. >> A key to reducing rolling friction is to work with hard surfaces. >> Another key >> to reducing friction in general (if possible) is to reduce the normal >> force. Both >> are achievable by hanging a pendulum from a rare earth magnet, using the >> ferrous >> property of the tungsten carbide. >> In a brief experiment this morning I stuck a 1/2 in cylindrical rare >> earth >> magnet to the top of a steel door frame and then hung a ball point pen >> from the >> magnet. Discovered that the tungsten carbide tip of the pen could support >> about >> 100 grams of weight. Of course this arrangement is unsatisfactory for a >> seismometer because the physical pendulum that results (swinging pen) >> moves as a >> spherical pendulum. >> To get the required planar motion I took the refills of two pens and >> glued >> them together. The pair of pen points can support about 200 grams of an >> inertial >> mass while constrained to motion in a plane. >> The quality factor of this oscillator proved to be really high, with >> the unit >> swinging in observable free decay for many hundreds of cycles. It is >> clear then, >> that the friction is very small indeed, by (i) taking advantage of the >> hardness of >> both the magnet and the small tungsten carbide balls; and (ii) because the >> field >> gradient of the magnet provides support for much of the mass of the >> pendulum, so >> that the normal force is reduced as compared to most other configurations. >> For you folks who have played with various axis types, what do you >> think >> about this? >> Randall >> > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 06:20:27 -0600 Hi, I have been following this discussion with great interest. I have been wondering how you would control the rotation of the free end of the suspended pendulum? As Ted pointed out in his email, it rotated. How would one maintain the motion in a horizontal plane - - AND - - what kind (size, weight, &etc.) of coil. Of course, Meredith suggested a light bulb. I'm just trying to wrap my brain around this idea as a whole assembly. Best Regards, Jerry Payton
Hi,
 
I have been following this discussion with great interest.  I = have=20 been wondering how you would control the rotation of the free end of the = suspended pendulum?  As Ted pointed out in his email, it = rotated.  How=20 would one maintain the motion in a horizontal plane - - AND - - what = kind (size,=20 weight, &etc.) of coil.  Of course, Meredith suggested a light=20 bulb.
 
I'm just trying to wrap my brain around this idea as a whole=20 assembly.
 
Best Regards,
Jerry Payton
Subject: Re: idea for an axis From: ChrisAtUpw@....... Date: Fri, 9 Nov 2007 07:23:36 EST In a message dated 09/11/2007, gmvoeth@........... writes: DID you clean the ink off the tip before doing this ? Hi Geoff, The BIC pens have tungsten carbide balls. If you cut off the plastic ink holder, you can push out the 1 mm ball with a fine drill / piano wire. You can then clean everything with methylated spirits and reassemble it. The ball can be crimped or glued in position with two part acrylic adhesive. However, you can buy martensitic SS balls from _www.smallparts.com_ (http://www.smallparts.com) They are ferromagnetic. Regards, Chris Chapman
In a message dated 09/11/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>DID you=20 clean the ink off the tip
before doing this ?
Hi Geoff,
 
    The BIC pens have tungsten carbide balls. If yo= u=20 cut off the plastic ink holder, you can push out the 1 mm ball with a f= ine=20 drill / piano wire. You can then clean everything with methylated spirits an= d=20 reassemble it. The ball can be crimped or glued in position with two part=20 acrylic adhesive. 
 
    However, you can buy martensitic SS balls from=20= www.smallparts.com They are=20 ferromagnetic.
 
    Regards,
 
    Chris Chapman 
Subject: further magnet ideas From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 07:53:07 -0500 Hey, Don't know whether we qualify as 'great minds', but at least we're 'on the same sheet of music'. The first thing I thought about following the 'obvious standard pendulum' was whether the idea could be extended to verticals--just as Meredith suggested. Also, Chris alluded to another element of the idea--rolling cylinders. Before the 'dangling pen' I had noticed that two cylindrical rare earth magnets roll together nicely. If you make one stationary and 'ping' the other it oscillates nicely. What's the primary source of damping? Some is the rolling friction, and some derive from induced eddy current in earch. If we reduce the rolling part, who cares about the eddy current parts? After all, they are part of the desired Q-reduction that has become standard to eliminate transient response of the instrument. Thus an arrangement I think could have promise is the following. A few years ago, now retired Georgia Tech seismologist Tim Long (very highly honored in our state) sent me a picture of a vertical he designed. Unlike with most instruments that use Lucien LaCoste's famous zero-length spring, Tim put the 'approximate' zero-length spring (probably a screen door type) below the boom. This is accomplished by flex-pivot elastic strips at the short end (top) of the U-shaped steel iron strip that serves as the 'backbone' of the instrument. I believe that Tim's flex-pivot strips could be replaced with two rare-earth magnets, one 'stuck' to the top of the frame and the other glued to the non-sensor end of the required non-ferrous boom. The boom magnet would roll on the frame magnet, with the contact force being made small (the two trying to pull apart) by 'proper' placement of each of the magnets. You amateurs are 'like a fresh cool wind' on a 'hot-as-hell Georgia August afternoon' and I love your enthusiam toward what might to the 'pro's' look like hare-brained ideas. I look forward to additional brainstorming on these thoughts. Randall Subject: Re: idea for an axis From: ian ian@........... Date: Fri, 09 Nov 2007 13:14:28 +0000 Hi, just tried this idea with neodymium magnet, 1 pen, 2 straws and a small mass at the end. I get a period of 1.4 seconds and indeed it does go on for a while. Silly question coming up - please be merciful(!) - how can I turn this into a long period teleseismic device (period of 10s of seconds)? Thanks Ian ChrisAtUpw@....... wrote: > In a message dated 09/11/2007, gmvoeth@........... writes: > > DID you clean the ink off the tip > before doing this ? > > Hi Geoff, > > The BIC pens have tungsten carbide balls. If you cut off the > plastic ink holder, you can push out the 1 mm ball with a fine drill / > piano wire. You can then clean everything with methylated spirits and > reassemble it. The ball can be crimped or glued in position with two > part acrylic adhesive. > > However, you can buy martensitic SS balls from www.smallparts.com > They are ferromagnetic. > > Regards, > > Chris Chapman -- Hi,

just tried this idea with neodymium magnet, 1 pen, 2 straws and a small mass at the end.  I get a period of 1.4 seconds and indeed it does go on for a while.

Silly question coming up - please be merciful(!) - how can I turn this into a long period teleseismic device (period of 10s of seconds)?

Thanks

Ian

ChrisAtUpw@....... wrote:
In a message dated 09/11/2007, gmvoeth@........... writes:
DID you clean the ink off the tip
before doing this ?
Hi Geoff,
 
    The BIC pens have tungsten carbide balls. If you cut off the plastic ink holder, you can push out the 1 mm ball with a fine drill / piano wire. You can then clean everything with methylated spirits and reassemble it. The ball can be crimped or glued in position with two part acrylic adhesive. 
 
    However, you can buy martensitic SS balls from www.smallparts.com They are ferromagnetic.
 
    Regards,
 
    Chris Chapman 

--

Subject: ball issues From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 08:23:50 -0500 Geoff, I did not clean the ink from the ball of the pen. Should point out that issues of 'lubrication' are some of the least understood phenomena of the modern science era. As my fluids colleague expert here at Mercer points out (Dr. Loren Sumner, graduate of Georgia Tech), the explanation of bearing friction lubrication starts at the 'opposite end' of Reynolds number thinking as compared to Bernoulli's equation. Some physics types, ignorant of the real world, try to easily explain everything on the basis of the latter. Airplane lift is not to be simply explained on the basis of Bernoulli's equation. Anybody exposed to that foolishness ought to go complain to his teacher! What I can say about rolling friction involving 'clean' as opposed to 'fluid treated' surfaces is that the best we can at present hope for is empirical understanding. Readers may be interested in the paper I wrote that speaks to some of this at arxiv.org/abs/physics/0506143 Don't be turned off by the frontier-physics features of this paper; just look at the photo's to know that it deals with rolling friction. Also note that there are all kinds of differences depending on 'cleanliness'. Truly, as I have stated in the first chapter that I wrote of the book to be published in January by Nova Science Publishers, titled "Science education in the 21st century"--friction, friction everywhere but in our understanding". This chapter is titled "Building on old foundations with new technologies". For those who might be interested, I have posted many papers on my webpage at http://physics.mercer.edu/hpage/peters.html If you look carefully you might 'find a pony in that stall'. My two decades in Texas, surrounded by cowboys whom I now miss here in Georgia, I adopted an expression that is quite applicable to much of the science now practiced: "if you can't impress them with finesse, then baffle them with b.s.". I hope that at least some of my papers at the aforementioned site might by you guys that I appreciate like the range-hands, be viewed as having some degree of finesse. Randall P.S. Jerry, I hope that my other comments, submitted a short while ago, at least speak to your question. Subject: seismometer sensitivity--fundamental physics From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 08:35:16 -0500 Ian, Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period. This can be proven from the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector. They could be moire' pattern types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test). The Ronchi ruling works with white light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve. Randall Subject: Re: idea for an axis From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 07:39:46 -0600 I just tried using a round "donut" neodymium magnet pressed on the end of a ball point plastic shank, not the ink tube, but the pen itself. Thereby, having the complete pen suspended by two stacked rectangular neodymium magnets and having an attached magnet to the pendulum (pen shaft) on the opposite end. I passed the circular magnet through a coil of bulk wire, and got a meter deflection. It was minute, but possibly usable if amplified. No, Dr. Peters, I do not see an answer to my previous post. Sorry! I've only had one cup of coffee this morning. (Smile) Jerry
I just tried using a round "donut" neodymium magnet = pressed on=20 the end of a ball point plastic shank, not the ink tube, but the pen=20 itself. 
 
Thereby, having the complete pen suspended by two stacked = rectangular=20 neodymium magnets and having an attached magnet to the pendulum (pen = shaft) on=20 the opposite end.  
 
I passed the circular magnet through a coil of  = bulk  wire,=20 and got a meter deflection.  It was minute, but possibly = usable if=20 amplified. 
 
No, Dr. Peters, I do not see an answer to my previous post. =20 Sorry!   I've only had one cup of coffee this morning. = (Smile)
 
Jerry
 
Subject: Re: seismometer sensitivity--fundamental physics From: ian ian@........... Date: Fri, 09 Nov 2007 13:46:20 +0000 Hi, thanks for the reply. I did know that lengthening the pendulum also lengthens the period but to hang one from the top of my house has some practical problems(!). I had hoped there might be some other way of tackling the problem. The Volksmeter II seems to have a pendulum of around 0.5 meters but It's response goes out to 10s of seconds - http://www.rllinstruments.com/VMIIDSPg8.htm . So I guess I'm looking for some cheap/easy way of lengthening the period. I can't afford the $999 to buy it. :-( Thanks Ian Randall Peters wrote: >Ian, > Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period. This can be proven from >the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. > As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one >sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. > So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector. They could be moire' pattern >types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test). The Ronchi ruling works with white >light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve. > Randall > > > -- Hi,

thanks for the reply.  I did know that lengthening the pendulum also lengthens the period but to hang one from the top of my house has some practical problems(!).

I had hoped there might be some other way of tackling the problem.  The Volksmeter II seems to have a pendulum of around 0.5 meters but It's response goes out to 10s of seconds - http://www.rllinstruments.com/VMIIDSPg8.htm .  So I guess I'm looking for some cheap/easy way of lengthening the period.  I can't afford the $999 to buy it.  :-(

Thanks

Ian

Randall Peters wrote:
Ian,
    Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand.  The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period.  This can be proven from
the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial.
    As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom.  Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one
sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period.
   So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom.  There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector.   They could be moire' pattern
types with white light (incrediby simple) to function as a tsunami detector.  Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test).  The Ronchi ruling works with white
light!  Or the sensor might be capacitive in nature like my SDC array.  The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve.
   Randall

--

Subject: More productive exchange of ideas with graphics? From: John Lahr johnjan@........ Date: Fri, 09 Nov 2007 07:26:02 -0800 The discussion of various hinges and seismometer designs is very interesting, but in many cases I find it difficult to visualize the exact setup that is being described. A photograph or a sketch would be very helpful. One way to do this is to start a blog. It's easy to do at: http://blogger.com. I started a blog, just to see how it worked, and it only took a few minutes to add an entry. My "trial" entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer sensitivity--fundamental physics From: ian ian@........... Date: Fri, 09 Nov 2007 15:34:18 +0000 Hi, I think this morning's fog may be lifting. The idea, presumably, is that it is not used as a pendulum but as a plumb-bob. It points to the centre of the earth and, as the waves pass, the position of the centre of the earth moves relative to the local ground, causing the device to shift about. So absolute position measurement of the end of the device is best. I'll crawl back into my hole now... Ian Randall Peters wrote: >Ian, > Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period. This can be proven from >the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. > As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one >sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. > So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector. They could be moire' pattern >types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test). The Ronchi ruling works with white >light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve. > Randall > > > -- Hi,

I think this morning's fog may be lifting.  The idea, presumably, is that it is not used as a pendulum but as a plumb-bob.  It points to the centre of the earth and, as the waves pass, the position of the centre of the earth moves relative to the local ground, causing the device to shift about.  So absolute position measurement of the end of the device is best.

I'll crawl back into my hole now...

Ian



Randall Peters wrote:
Ian,
    Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand.  The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period.  This can be proven from
the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial.
    As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom.  Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one
sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period.
   So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom.  There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector.   They could be moire' pattern
types with white light (incrediby simple) to function as a tsunami detector.  Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test).  The Ronchi ruling works with white
light!  Or the sensor might be capacitive in nature like my SDC array.  The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve.
   Randall

--

Subject: Re: More productive exchange of ideas with graphics? From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 09:46:29 -0600 John, I agree that visualization is VERY difficult sometimes, but I hesitate creating a separate blog since it might water down the discussions here. People might move to the blogs instead of here and some might be left out of the comments. I am doing a "desktop experiment" right now with this and it would best be show rather than described. I am suspending a ball point pen, as discussed. On the other end of the pen is a ring magnet which is suspended about 1/2" above the edge of a spool of bulk wire, which is connected directly connected to my electronics. Thus far, it detects my walking up to the desk and other movements. I am allowing some time to see if an EQ event happens (I hope). Of course, it is not damped and movement could be in any direction. I haven't crossed that bridge yet. Jerry ----- Original Message ----- From: John Lahr To: psn-l@.............. Sent: Friday, November 09, 2007 9:26 AM Subject: More productive exchange of ideas with graphics? The discussion of various hinges and seismometer designs is very interesting, but in many cases I find it difficult to visualize the exact setup that is being described. A photograph or a sketch would be very helpful. One way to do this is to start a blog. It's easy to do at: http://blogger.com. I started a blog, just to see how it worked, and it only took a few minutes to add an entry. My "trial" entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
John,
 
I agree that visualization is VERY difficult sometimes, but I=20 hesitate creating a separate blog since it might water down = the=20 discussions here.  People might move to the blogs instead of here = and some=20 might be left out of the comments.
 
I am doing a "desktop experiment" right now with this and it would = best be=20 show rather than described.  I am suspending a ball point pen, as=20 discussed.  On the other end of the pen is a ring magnet which is = suspended=20 about 1/2" above the edge of a spool of bulk wire, which is = connected=20 directly connected to my electronics.
 
Thus far, it detects my walking up to the desk and other = movements.  I=20 am allowing some time to see if an EQ event happens (I hope).  Of = course,=20 it is not damped and movement could be in any direction.  I haven't = crossed=20 that bridge yet.
 
Jerry
 
 
----- Original Message -----=20
From: John Lahr =
Sent: Friday, November 09, 2007 9:26 AM
Subject: More productive exchange of ideas with=20 graphics?

The discussion of various hinges and seismometer designs = is very=20
interesting, but in many cases I find it difficult to visualize the=20
exact setup that is being described.  A photograph or a sketch = would=20
be very helpful.

One way to do this is to start a blog.  = It's=20 easy to do
at:  http://blogger.com.  I started a = blog, just=20 to see how it
worked, and it only took a few minutes to add an = entry. =20 My "trial"
entry shows the AS-1 sensor:  http://seismoedu.blogspot.com/

I'm=20 sure there are other posting options as=20 well.

Cheers,
John


_________________________________= _________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: RE: More productive exchange of ideas with graphics? From: "Keith Payea" kpayea@.............. Date: Fri, 9 Nov 2007 08:26:52 -0800 All: One person's problem is another's data. Instead of trying to constrain the movement to one direction, try to figure out a way to measure the displacement direction as well as amplitude. Then one could detect earthquakes from any direction and know something about the direction the waves were travelling. Just throwing another log on this bonfire, I'm afraid... Keith _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Jerry Payton Sent: Friday, November 09, 2007 7:46 AM To: psn-l@.............. Subject: Re: More productive exchange of ideas with graphics? John, I agree that visualization is VERY difficult sometimes, but I hesitate creating a separate blog since it might water down the discussions here. People might move to the blogs instead of here and some might be left out of the comments. I am doing a "desktop experiment" right now with this and it would best be show rather than described. I am suspending a ball point pen, as discussed. On the other end of the pen is a ring magnet which is suspended about 1/2" above the edge of a spool of bulk wire, which is connected directly connected to my electronics. Thus far, it detects my walking up to the desk and other movements. I am allowing some time to see if an EQ event happens (I hope). Of course, it is not damped and movement could be in any direction. I haven't crossed that bridge yet. Jerry ----- Original Message ----- From: John Lahr To: psn-l@.............. Sent: Friday, November 09, 2007 9:26 AM Subject: More productive exchange of ideas with graphics? The discussion of various hinges and seismometer designs is very interesting, but in many cases I find it difficult to visualize the exact setup that is being described. A photograph or a sketch would be very helpful. One way to do this is to start a blog. It's easy to do at: http://blogger.com. I started a blog, just to see how it worked, and it only took a few minutes to add an entry. My "trial" entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
All:
 
One person's problem is another's data.  = Instead of=20 trying to constrain the movement to one direction, try to figure out a = way to=20 measure the displacement direction as well as amplitude.  Then one = could=20 detect earthquakes from any direction and know something about the = direction the=20 waves were travelling.
 
Just throwing another log on this bonfire, I'm=20 afraid...
 
    Keith

From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of Jerry=20 Payton
Sent: Friday, November 09, 2007 7:46 AM
To:=20 psn-l@..............
Subject: Re: More productive exchange of = ideas=20 with graphics?

John,
 
I agree that visualization is VERY difficult sometimes, but I=20 hesitate creating a separate blog since it might water down = the=20 discussions here.  People might move to the blogs instead of here = and some=20 might be left out of the comments.
 
I am doing a "desktop experiment" right now with this and it would = best be=20 show rather than described.  I am suspending a ball point pen, as=20 discussed.  On the other end of the pen is a ring magnet which is = suspended=20 about 1/2" above the edge of a spool of bulk wire, which is = connected=20 directly connected to my electronics.
 
Thus far, it detects my walking up to the desk and other = movements.  I=20 am allowing some time to see if an EQ event happens (I hope).  Of = course,=20 it is not damped and movement could be in any direction.  I haven't = crossed=20 that bridge yet.
 
Jerry
 
 
----- Original Message -----=20
From: John Lahr =
Sent: Friday, November 09, 2007 9:26 AM
Subject: More productive exchange of ideas with=20 graphics?

The discussion of various hinges and seismometer designs = is very=20
interesting, but in many cases I find it difficult to visualize the=20
exact setup that is being described.  A photograph or a sketch = would=20
be very helpful.

One way to do this is to start a blog.  = It's=20 easy to do
at:  http://blogger.com.  I started a = blog, just=20 to see how it
worked, and it only took a few minutes to add an = entry. =20 My "trial"
entry shows the AS-1 sensor:  http://seismoedu.blogspot.com/

I'm=20 sure there are other posting options as=20 well.

Cheers,
John


_________________________________= _________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:25:24 -0700 Hello PSN; You guys sound more like scientists than laymen ?? Sort of like the American Association for the Advancement of Science that once showed on a cover of their magazine the secrets of how a thermo-nuke is first initiated by converging shock waves of a detonated wafer of high explosive looked at through some kind of XRAY photography. It made me think of how Tim McVey might have improved the performance of his already deadly explosives. I am not sure you want to make motion just be all in one axis of motion I have in the past had very good EQ signatures using a free hanging pendulum with a 5 lb lead mass which had a circular speaker magnet attached. It was damped in synthetic motor oil and free to move over the coil in any horizontal direction. You do not know the direction of motion you only see the various phases as well as first time of arrival. I have never understood the amature infatuation with knowing all the fine details when they are really not necessary to keep a layman happy. Also I have been looking at free periods in relation to gravity and how to oppose or reduce the 32.17fpss to more like 18.9 inpss I am thinking in terms of maybe a five pound mass with a specific gravity of like 1.0516 or so that could be immersed in pure water and use a very delicate spring extended by 12 inches to get a 5 second period or so. There must be some way to emulate specific gravity by the use of bouyancy ( eg using a cylinder or cone or other primative shape to displace water and achieve the right response in free period. I am looking for a cheap way to get maybe 4 second period so I do not need to filter or equalize when I amplify( except anti-alise). It seems there are many different ways to attack this problem and I am certain it has been done so before, so why do we not see any basic research on the part of science to invent the best and cheapest vertical sensor. I really like a free swinging pendulum ( just the horizontal ) and free vertical whatever. with a magnetic damper but not sure the best magnet coil relationship to get the best signal strength. Such a thing in a vacuum and properly shielded should be free of most interference. I guess I am two dimensional in my thinking and not three like the rest of you. The best of all sensors would just be a single unit to measure motion no matter what the dimension it happens in. Now I am ALL DIMENSIONAL and after thinking out loud was wondering to you guys if such an all dimensional ( single unit ) velocity sensor has ever been made ?? Possibly a mass suspended in a magnetic field to be restored to a fixed point in some strange fashion I have never seen ?? Sort of like that (REAL) levitating ball in the movie "Flying Saucers Vs The Earth" This is not a free period kind of issue but more the energy required to recenter the mass once it has been disturbed in whatever direction. Any Thoughts about any of this ? I know where I stand on this world so please do not make fun unless I can laugh too :-) Is there any reason to keep Seismometer Research Secret ?? Almost noone wants these things. Regards geoff ----- Original Message ----- From: "Jerry Payton" To: Sent: Friday, November 09, 2007 5:20 AM Subject: Re: idea for an axis > Hi, > > I have been following this discussion with great interest. I have been > wondering how you would control the rotation of the free end of the > suspended pendulum? As Ted pointed out in his email, it rotated. How would > one maintain the motion in a horizontal plane - - AND - - what kind (size, > weight, &etc.) of coil. Of course, Meredith suggested a light bulb. > > I'm just trying to wrap my brain around this idea as a whole assembly. > > Best Regards, > Jerry Payton > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: Dave Youden dyouden@............. Date: Fri, 09 Nov 2007 11:36:12 -0500 John has a good idea. After reading his post I went to blogger and posted some pictures of the two seismos that I am currently operating. Go to http://MarvelousMachines.blogspot.com To view them. I hope that this prompts others to do the same. Dave... John Lahr wrote: > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do at: > http://blogger.com. I started a blog, just to see how it worked, and > it only took a few minutes to add an entry. My "trial" entry shows > the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > -- David H. Youden Olympic Precision, Inc. WTC LLC 43 Pine Street White River Junction, VT 05001 Office tel: 802-291-7007 Office fax: 802-291-7009 Home office: 802-484-5423 Home fax: 802-484-5429 Cellular: 802-952-8121 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:33:12 -0700 You must find some way to reduce the pull of gravity to meet the formula P=2Pisqrt(Length(inches)/386.04)) That Is the ONLY thing I understand. The 386.04 must be more like 3 inchespss or maybe like the effects of gravity on an incline like one degree from the vertical. There are many ways to do this but none seem to be cheap for a person living on 12K a year. ----- Original Message ----- From: "ian" To: Sent: Friday, November 09, 2007 6:14 AM Subject: Re: idea for an axis > Hi, > > just tried this idea with neodymium magnet, 1 pen, 2 straws and a small > mass at the end. I get a period of 1.4 seconds and indeed it does go on > for a while. > > Silly question coming up - please be merciful(!) - how can I turn this > into a long period teleseismic device (period of 10s of seconds)? > > Thanks > > Ian > > ChrisAtUpw@....... wrote: > >> In a message dated 09/11/2007, gmvoeth@........... writes: >> >> DID you clean the ink off the tip >> before doing this ? >> >> Hi Geoff, >> >> The BIC pens have tungsten carbide balls. If you cut off the >> plastic ink holder, you can push out the 1 mm ball with a fine drill / >> piano wire. You can then clean everything with methylated spirits and >> reassemble it. The ball can be crimped or glued in position with two >> part acrylic adhesive. >> >> However, you can buy martensitic SS balls from www.smallparts.com >> They are ferromagnetic. >> >> Regards, >> >> Chris Chapman > > > -- > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: ChrisAtUpw@....... Date: Fri, 9 Nov 2007 11:36:59 EST In a message dated 09/11/2007, kpayea@.............. writes: One person's problem is another's data. Instead of trying to constrain the movement to one direction, try to figure out a way to measure the displacement direction as well as amplitude. Then one could detect earthquakes from any direction and know something about the direction the waves were travelling. Hi Keith, How about putting four magnets on the bottom of the bob and using figure of 8 coils? Alternatively one central magnet and four coils overlapping the edges? Regards, Chris Chapman
In a message dated 09/11/2007, kpayea@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
One person's problem is another's data.  Ins= tead of=20 trying to constrain the movement to one direction, try to figure out a way= to=20 measure the displacement direction as well as amplitude.  Then one co= uld=20 detect earthquakes from any direction and know something about the directi= on=20 the waves were travelling.
Hi Keith,
 
    How about putting four magnets on the bottom of= the=20 bob and using figure of 8 coils? Alternatively one central magnet and f= our=20 coils overlapping the edges?
 
    Regards,
 
    Chris Chapman
Subject: Re: More productive exchange of ideas with graphics? From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:38:56 -0700 You can imagine the wave as a straight line approaching and according to the times received at different stations know direction by the displacement in time between two stations using only first time of arrival. With two stations you get two possibilities with direction and distance but more than likely only one direction will be the Common EQ area. As long as no human is playing games with your station you should be able to have faith in your results. ----- Original Message ----- From: "Keith Payea" To: Sent: Friday, November 09, 2007 9:26 AM Subject: RE: More productive exchange of ideas with graphics? > All: > > One person's problem is another's data. Instead of trying to constrain the > movement to one direction, try to figure out a way to measure the > displacement direction as well as amplitude. Then one could detect > earthquakes from any direction and know something about the direction the > waves were travelling. > > Just throwing another log on this bonfire, I'm afraid... > > Keith > > _____ > > From: psn-l-request@.............. [mailto:psn-l-request@............... On > Behalf Of Jerry Payton > Sent: Friday, November 09, 2007 7:46 AM > To: psn-l@.............. > Subject: Re: More productive exchange of ideas with graphics? > > > John, > > I agree that visualization is VERY difficult sometimes, but I hesitate > creating a separate blog since it might water down the discussions here. > People might move to the blogs instead of here and some might be left out of > the comments. > > I am doing a "desktop experiment" right now with this and it would best be > show rather than described. I am suspending a ball point pen, as discussed. > On the other end of the pen is a ring magnet which is suspended about 1/2" > above the edge of a spool of bulk wire, which is connected directly > connected to my electronics. > > Thus far, it detects my walking up to the desk and other movements. I am > allowing some time to see if an EQ event happens (I hope). Of course, it is > not damped and movement could be in any direction. I haven't crossed that > bridge yet. > > Jerry > > > ----- Original Message ----- > From: John Lahr > To: psn-l@.............. > Sent: Friday, November 09, 2007 9:26 AM > Subject: More productive exchange of ideas with graphics? > > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do > at: http://blogger.com. I started a blog, just to see how it > worked, and it only took a few minutes to add an entry. My "trial" > entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:44:08 -0700 I use my personal website to post images. For small numbers of interested persons this way seems best since most internet users are given a PWP as common practice. So long as the general public does not attack your site this is the most private way of sharing info. I once went on a USENET virus group and attacked virus writers after which I was flooded with all sorts of viruses one that got past a company scanner because it was so new. :-( Never Been infected except maybe with Magic Lantern ??? ----- Original Message ----- From: "John Lahr" To: Sent: Friday, November 09, 2007 8:26 AM Subject: More productive exchange of ideas with graphics? > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do > at: http://blogger.com. I started a blog, just to see how it > worked, and it only took a few minutes to add an entry. My "trial" > entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:46:58 -0700 If you could build a device with like 0.7 Q that is natural Friction or ?? then you need to rob no energy from the detector to create a signal. Better signal to noise ratio I would think. ----- Original Message ----- From: "Jerry Payton" To: Sent: Friday, November 09, 2007 8:46 AM Subject: Re: More productive exchange of ideas with graphics? > John, > > I agree that visualization is VERY difficult sometimes, but I hesitate > creating a separate blog since it might water down the discussions here. > People might move to the blogs instead of here and some might be left out of > the comments. > > I am doing a "desktop experiment" right now with this and it would best be > show rather than described. I am suspending a ball point pen, as discussed. > On the other end of the pen is a ring magnet which is suspended about 1/2" > above the edge of a spool of bulk wire, which is connected directly > connected to my electronics. > > Thus far, it detects my walking up to the desk and other movements. I am > allowing some time to see if an EQ event happens (I hope). Of course, it is > not damped and movement could be in any direction. I haven't crossed that > bridge yet. > > Jerry > > > ----- Original Message ----- > From: John Lahr > To: psn-l@.............. > Sent: Friday, November 09, 2007 9:26 AM > Subject: More productive exchange of ideas with graphics? > > > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do > at: http://blogger.com. I started a blog, just to see how it > worked, and it only took a few minutes to add an entry. My "trial" > entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer sensitivity--fundamental physics From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:49:37 -0700 Then you got to worry about the Earths Rotation affecting the direction of the pendulum. ?? ----- Original Message ----- From: "Randall Peters" To: Sent: Friday, November 09, 2007 6:35 AM Subject: seismometer sensitivity--fundamental physics > Ian, > Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The > sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the > square of the period. This can be proven from > the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. > As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the > instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of > the ratio of length to earth field (little g), one > sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. > So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your > sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective > earthquake detector. They could be moire' pattern > types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means > of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge > test). The Ronchi ruling works with white > light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest > in the serendipty that is likely to come out of the listserve. > Randall > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer sensitivity--fundamental physics From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:50:47 -0700 More than 4 or 5 seconds is a waste of time and money to deal with. ----- Original Message ----- From: "ian" To: Sent: Friday, November 09, 2007 6:46 AM Subject: Re: seismometer sensitivity--fundamental physics > Hi, > > thanks for the reply. I did know that lengthening the pendulum also > lengthens the period but to hang one from the top of my house has some > practical problems(!). > > I had hoped there might be some other way of tackling the problem. The > Volksmeter II seems to have a pendulum of around 0.5 meters but It's > response goes out to 10s of seconds - > http://www.rllinstruments.com/VMIIDSPg8.htm . So I guess I'm looking > for some cheap/easy way of lengthening the period. I can't afford the > $999 to buy it. :-( > > Thanks > > Ian > > Randall Peters wrote: > >>Ian, >> Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The >> sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the >> square of the period. This can be proven from >>the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. >> As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the >> instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of >> the ratio of length to earth field (little g), one >>sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. >> So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your >> sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective >> earthquake detector. They could be moire' pattern >>types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means >>of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge >>test). The Ronchi ruling works with white >>light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest >>in the serendipty that is likely to come out of the listserve. >> Randall >> >> >> > > -- > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: further magnet ideas From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 10:01:33 -0700 Hi Randall and all, As far as utilizing a "crossed rod" pivot/axis (crossed/rolling cylinders) of neo magnets, the standard neo magnet has its poles on the ends of these rods/cylinders...making it somewhat difficult to do much with them. Forcefield magnets (http://forcefieldmagnets.com) does have a 1/4" diameter x 1" length (gold plating...of course..ha) magnet were the magnets poles are through the diameter. It is item #0056, and sells for $3. This would make perhaps right angle positioning one magnet across 2 other magnets of the same polarization alot easier....(who knows they might center pretty good?). Of course the gold plating isn't a hard surface; but it might make for a interesting axis/pivot as the "mass" weights will be fairly limited anyway. Generally....the gold plate "could" peel off after time or from impact abuse more easily than the standard chrome plating. I "think" this could be what Chris Chapman has in mind? These were most useful for diamagnetically levitating select pencil leads afew years back. Unlike some magnets; these have been around for a number of years and I doubt Forcefield will drop selling them anytime soon. I'd think the axis/pivot application could be used for both a hanging horizontal...and perhaps a vertical axis/pivot also. Meredith Lamb On Nov 9, 2007 5:53 AM, Randall Peters wrote: > > Hey, > Don't know whether we qualify as 'great minds', but at least we're 'on > the same sheet of music'. The first thing I thought about following the > 'obvious standard pendulum' was whether the idea could be extended to > verticals--just as Meredith suggested. Also, Chris alluded to another > element of the > idea--rolling cylinders. > Before the 'dangling pen' I had noticed that two cylindrical rare earth > magnets roll together nicely. If you make one stationary and 'ping' the > other it oscillates nicely. What's the primary source of damping? Some is > the rolling friction, and some derive from induced eddy current in earch. > If > we reduce the rolling part, who cares about the eddy current parts? After > all, they are part of the desired Q-reduction that has become standard to > eliminate transient response of the instrument. Thus an arrangement I think > could have promise is the following. > A few years ago, now retired Georgia Tech seismologist Tim Long (very > highly honored in our state) sent me a picture of a vertical he designed. > Unlike with most instruments that use Lucien LaCoste's famous zero-length > spring, Tim put the 'approximate' zero-length spring (probably a screen door > type) below the boom. This is accomplished by flex-pivot elastic strips > at the short end (top) of the U-shaped steel iron strip that serves as the > 'backbone' of the instrument. > I believe that Tim's flex-pivot strips could be replaced with two > rare-earth magnets, one 'stuck' to the top of the frame and the other glued > to the non-sensor end of the required non-ferrous boom. The boom magnet > would roll on the frame magnet, with the contact force being made small (the > two > trying to pull apart) by 'proper' placement of each of the magnets. > You amateurs are 'like a fresh cool wind' on a 'hot-as-hell Georgia > August afternoon' and I love your enthusiam toward what might to the 'pro's' > look like hare-brained ideas. I look forward to additional brainstorming on > these thoughts. > Randall > >
Hi Randall and all,
 
As far as utilizing a "crossed rod" pivot/axis (crossed/rolling cylinders) of neo magnets, the standard
neo magnet has its poles on the ends of these rods/cylinders...making it somewhat difficult to do much
with them.  Forcefield magnets (http://forcefieldmagnets.com) does have a 1/4" diameter x 1"
length (gold plating...of course..ha) magnet were the magnets poles are through the diameter. 
It is item #0056, and sells for $3.  This would make perhaps right angle positioning one magnet
across 2 other magnets of the same polarization alot easier....(who knows they might center pretty
good?).  Of course the gold plating isn't a hard surface; but it might make for a interesting axis/pivot
as the "mass" weights will be fairly limited anyway.   Generally....the gold plate "could" peel off
after time or from impact abuse more easily than the standard chrome plating.
 
I "think" this could be what Chris Chapman has in mind?  These were most useful for diamagnetically
levitating select pencil leads afew years back.  Unlike some magnets; these have been around
for a number of years and I doubt Forcefield will drop selling them anytime soon.   
 
I'd think the axis/pivot application could be used for both a hanging horizontal...and perhaps a vertical
axis/pivot also.
 
Meredith Lamb 

On Nov 9, 2007 5:53 AM, Randall Peters <PETERS_RD@..........> wrote:

Hey,
   Don't know whether we qualify as 'great minds', but at least we're 'on the same sheet of music'.  The first thing I thought about following the 'obvious standard pendulum' was whether the idea could be extended to verticals--just as Meredith suggested.  Also, Chris alluded to another element of the
idea--rolling cylinders.
   Before the 'dangling pen' I had noticed that two cylindrical rare earth magnets roll together nicely.  If you make one stationary and 'ping' the other it oscillates nicely.  What's the primary source of damping?   Some is the rolling friction, and some derive from induced eddy current in earch.  If
we reduce the rolling part, who cares about the eddy current parts?  After all, they are part of the desired Q-reduction that has become standard to eliminate transient response of the instrument.  Thus an arrangement I think could have promise is the following.
   A few years ago, now retired Georgia Tech seismologist Tim Long (very highly honored in our state) sent me a picture of a vertical he designed.  Unlike with most instruments that use Lucien LaCoste's famous zero-length spring, Tim put the 'approximate' zero-length spring (probably a screen door
type) below the boom.  This is accomplished by flex-pivot elastic strips at the short end (top) of the U-shaped steel iron strip that serves as the 'backbone' of the instrument.
   I believe that Tim's flex-pivot strips could be replaced with two rare-earth magnets, one 'stuck' to the top of the frame and the other glued to the non-sensor end of the required non-ferrous boom.  The boom magnet would roll on the frame magnet, with the contact force being made small (the two
trying to pull apart) by 'proper' placement of each of the magnets.
  You amateurs are 'like a fresh cool wind' on a 'hot-as-hell Georgia August afternoon' and I love your enthusiam toward what might to the 'pro's' look like hare-brained ideas.  I look forward to additional brainstorming on these thoughts.
   Randall


Subject: long-period pendulums From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 13:15:30 -0500 I noticed the interest in period lengthening of a compound pendulum, as though any such change toward long period would be an advantage. Unfortunately, this is not the case. I have spent the biggest part of my career studying internal friction using the rod-pendulum-types in which there is a mass located above the axis as well as below. Although the period can be made very long, it does not result in an increased sensitivity in accord with what is experienced with the simple pendulum This style of pendulum is an entirely different system than the folded pendulum, which I have also researched. As a compact unit, the folded pendulum can be made very sensitive. There can be an advantage to the use of the long-period rod pendulum, but not in the traditional seismic sense. I wrote a paper titled "Compound pendulum to monitor hurricanes and tropical storms", online at http://arxiv.org/abs/physics/0610092 and which uses such a pendulum. For those who want to understand the physics behind my preceding comments, this paper provides the details. To appreciate the lack of sensitivity (to anything other than really, really low frequency drive, including tilt), consider the following. Imagine a rod in which the axis approaches the center of mass. The period thus approaches infinity; so you might expect it to have really great sensitivity. The problem with the rod pendulum is it becomes very sensitive to internal structural change while having little sensitivity to high frequency seismic activity. In fact, the sensitivity at frequencies above the very low eigenfrequency is virtually zero. The reason is obvious. If you accelerate an extended object with a force that goes through the center of mass, it does not rotate. Thus it cannot serve as a seismometer. Guess you know already that some mechanical systems can be intuitively hard to understand if not downright baffling! Before I was able to really appreciate what was happening with this pendulum, as relates to seismic sensing, I had to thoroughly describe it with the tools of physics; i.e., mathematics. Only afterwards was I able to conceptually appreciate its properties. There was a comment about the VolksMeter. How can it, through 'period extension' operate well in spite of a pendulum less than a meter in length. The key is in what is done digitally. The raw data output is not good for teleseismic viewing, where sensitivity is a must. But the integral of that data alters the response of the instrument (same as is done in the Shackleford-Gunderson). The Bode plot falls off with frequency, allowing the 20 s period teleseisms to be seen above noise in many cases, for M 6 or more. It is not a case in which the increased SNR derives from the pendulum; rather it derives from the electronics employed. Even force-balance commercial units rely on electronics to give great response even though the eigenfrequency of the non-feedback instrument is too high for good performance. There the tailoring of both lower corner frequency and damping is accomplished by means of the negative feedback employed. Randall Subject: Re: further magnet ideas From: Charles Patton charles.r.patton@........ Date: Fri, 09 Nov 2007 10:32:48 -0800 One thought that occurs to me is to start with a rail of steel angle iron (for a flux return) then add the two "pills" that Meredith mentions below separated by some distance (the length of your pivot) and installed with one N and one S down to the rail. On top of the magnets get some of the flat carbide blades that are replacement parts for some paint scrapers. These are triangular (I seem to remember -- I'm traveling so I can't go look at them at the moment) about 1" on a side and about 0.020" thick. I bought some from ACE hardware, but they're probably also available from Home Depot style stores. The key here is that the angle iron rail gives a flat common reference surface from a geometry viewpoint and has enough bulk for a good flux return. The carbide scraper blades give you the hard, low rolling friction surface -- better than the gold or the composition of the magnet. As a side point, one of the reasons the high strength magnets are plated with nickel or gold is that their alloys are particularly subject to corrosion, hence require plating to protect them. I strongly recommend not removing the "gold" coating as it would make the magnets subject to atmospheric deterioration. Charles Patton meredith lamb wrote: > Hi Randall and all, > > As far as utilizing a "crossed rod" pivot/axis (crossed/rolling > cylinders) of neo magnets, the standard > neo magnet has its poles on the ends of these rods/cylinders...making it > somewhat difficult to do much > with them. Forcefield magnets (http://forcefieldmagnets.com > ) does have a 1/4" diameter x 1" > length (gold plating...of course..ha) magnet were the magnets poles are > through the diameter. > It is item #0056, and sells for $3. This would make perhaps right angle > positioning one magnet > across 2 other magnets of the same polarization alot easier....(who > knows they might center pretty > good?). Of course the gold plating isn't a hard surface; but it might > make for a interesting axis/pivot > as the "mass" weights will be fairly limited anyway. Generally....the > gold plate "could" peel off > after time or from impact abuse more easily than the standard chrome > plating. > > I "think" this could be what Chris Chapman has in mind? These were most > useful for diamagnetically > levitating select pencil leads afew years back. Unlike some magnets; > these have been around > for a number of years and I doubt Forcefield will drop selling them > anytime soon. > > I'd think the axis/pivot application could be used for both a hanging > horizontal...and perhaps a vertical > axis/pivot also. > > Meredith Lamb > > On Nov 9, 2007 5:53 AM, Randall Peters > wrote: > > > Hey, > Don't know whether we qualify as 'great minds', but at least > we're 'on the same sheet of music'. The first thing I thought about > following the 'obvious standard pendulum' was whether the idea could > be extended to verticals--just as Meredith suggested. Also, Chris > alluded to another element of the > idea--rolling cylinders. > Before the 'dangling pen' I had noticed that two cylindrical rare > earth magnets roll together nicely. If you make one stationary and > 'ping' the other it oscillates nicely. What's the primary source of > damping? Some is the rolling friction, and some derive from > induced eddy current in earch. If > we reduce the rolling part, who cares about the eddy current parts? > After all, they are part of the desired Q-reduction that has become > standard to eliminate transient response of the instrument. Thus an > arrangement I think could have promise is the following. > A few years ago, now retired Georgia Tech seismologist Tim Long > (very highly honored in our state) sent me a picture of a vertical > he designed. Unlike with most instruments that use Lucien LaCoste's > famous zero-length spring, Tim put the 'approximate' zero-length > spring (probably a screen door > type) below the boom. This is accomplished by flex-pivot elastic > strips at the short end (top) of the U-shaped steel iron strip that > serves as the 'backbone' of the instrument. > I believe that Tim's flex-pivot strips could be replaced with two > rare-earth magnets, one 'stuck' to the top of the frame and the > other glued to the non-sensor end of the required non-ferrous boom. > The boom magnet would roll on the frame magnet, with the contact > force being made small (the two > trying to pull apart) by 'proper' placement of each of the magnets. > You amateurs are 'like a fresh cool wind' on a 'hot-as-hell > Georgia August afternoon' and I love your enthusiam toward what > might to the 'pro's' look like hare-brained ideas. I look forward > to additional brainstorming on these thoughts. > Randall > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Exchange of ideas with graphics From: "Kay Wyatt" kwyatt@............. Date: Fri, 9 Nov 2007 10:57:42 -0800 To all PSN folks, I joined the PSN group in September and must say that I have learned = much from everybody and I am indeed grateful. I am running my own AS-1. = However, thanks to so many advisors, I am currently constructing both a = vertical and horizontal sensor based on the collective knowledge of many = of you. Picking up knowledge from the PSN-net is like drinking through a fire = hydrant. I have especially had problems visualizing the suggested = designs with a text-only system. After emailing several PSN folks = directly for drawings, I have had many "Aha" moments when receiving = graphics. The PSN mail list doesn't allow graphics to be sent directly. Sending = hyperlinks to drawings and photos on our individual websites works very = well. But many PSN folks do not have personal websites. The PSN system allows for graphics distribution as follows (from the PSN = Welcome email): 6) Send only TEXT messages to the list. Do not include any attachments, HTML tags (this is referring to HTML code not links),=20 or so forth. If you have a picture, or other binary type files=20 to share with the group, you can uploaded when using FTP to ftp://ftp.seismicnet.com/info. See below for more information.=20 Has anybody been able to send graphics to the PSN ftp site? When I ftp = to the site I am asked for account and password. . I agree with Jerry (below) that I would worry about using John Lahr's = blog site INSTEAD of the PSN. But what about using it WITH the PSN = email system. That is, to upload a drawing to the blog and reference it = with a hyperlink to the blog site? I look forward to hearing any further discussion on this important = issue. By the way, are there any other women amateur seismologists on this = list? How many of you guys have shared your hobby with your daughters? = ;-) Kay Wyatt ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Friday, November 09, 2007 7:46 AM Subject: Re: More productive exchange of ideas with graphics? John, I agree that visualization is VERY difficult sometimes, but I hesitate = creating a separate blog since it might water down the discussions here. = People might move to the blogs instead of here and some might be left = out of the comments. I am doing a "desktop experiment" right now with this and it would = best be show rather than described. I am suspending a ball point pen, = as discussed. On the other end of the pen is a ring magnet which is = suspended about 1/2" above the edge of a spool of bulk wire, which is = connected directly connected to my electronics. Thus far, it detects my walking up to the desk and other movements. I = am allowing some time to see if an EQ event happens (I hope). Of = course, it is not damped and movement could be in any direction. I = haven't crossed that bridge yet. Jerry ----- Original Message -----=20 From: John Lahr=20 To: psn-l@................. Sent: Friday, November 09, 2007 9:26 AM Subject: More productive exchange of ideas with graphics? The discussion of various hinges and seismometer designs is very=20 interesting, but in many cases I find it difficult to visualize the=20 exact setup that is being described. A photograph or a sketch would=20 be very helpful. One way to do this is to start a blog. It's easy to do=20 at: http://blogger.com. I started a blog, just to see how it=20 worked, and it only took a few minutes to add an entry. My "trial"=20 entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with=20 the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information.
To all PSN folks,
 
I joined the PSN group in September and must say = that I=20 have learned much from everybody and I am indeed grateful.  I am = running my=20 own AS-1.  However, thanks to so many advisors, I am currently = constructing=20 both a vertical and horizontal sensor based on the collective knowledge = of many=20 of you.
 
Picking up knowledge from the PSN-net is like = drinking=20 through a fire hydrant.  I have especially had problems visualizing = the=20 suggested designs with a text-only system.  After emailing several = PSN=20 folks directly for drawings, I have had many "Aha" moments when = receiving=20 graphics.
 
The PSN mail list doesn't allow graphics to be = sent=20 directly.  Sending hyperlinks to drawings and photos on our = individual=20 websites works very well.  But many PSN folks do not have personal=20 websites.
 
The PSN system allows for graphics distribution = as follows=20 (from the PSN Welcome email):
 
6)  Send only TEXT messages to the list.  Do not include=20 any
    attachments, HTML tags (this is referring to = HTML code=20 not links),
    or so forth. If you have a picture, = or other=20 binary type files
    to share with the group, you = can=20 uploaded when using FTP to
    ftp://ftp.seismicnet.com/info.= See=20 below for more information.
Has anybody been able to send graphics to the = PSN ftp=20 site?  When I ftp to the site I am asked for account and = password. =20 ..
 
I agree with Jerry (below) that I would worry = about using=20 John Lahr's blog site INSTEAD of the PSN.  But what about using it = WITH the=20 PSN email system.  That is, to upload a drawing to the blog and = reference=20 it with a hyperlink to the blog site?
 
I look forward to hearing any further discussion = on this=20 important issue.
 
By the way, are there any other women amateur=20 seismologists on this list?  How many of you guys have shared your = hobby=20 with  your daughters?    ;-)
 
Kay Wyatt
 
 
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Friday, November 09, 2007 = 7:46=20 AM
Subject: Re: More productive = exchange of=20 ideas with graphics?

John,
 
I agree that visualization is VERY difficult sometimes, but = I=20 hesitate creating a separate blog since it might water down = the=20 discussions here.  People might move to the blogs instead of here = and=20 some might be left out of the comments.
 
I am doing a "desktop experiment" right now with this and it = would best=20 be show rather than described.  I am suspending a ball point pen, = as=20 discussed.  On the other end of the pen is a ring magnet which is = suspended about 1/2" above the edge of a spool of bulk wire, = which is=20 connected directly connected to my electronics.
 
Thus far, it detects my walking up to the desk and other = movements. =20 I am allowing some time to see if an EQ event happens (I hope).  = Of=20 course, it is not damped and movement could be in any direction.  = I=20 haven't crossed that bridge yet.
 
Jerry
 
 
----- Original Message -----=20
From: John = Lahr
Sent: Friday, November 09, 2007 9:26 AM
Subject: More productive exchange of ideas with=20 graphics?

The discussion of various hinges and seismometer = designs is=20 very
interesting, but in many cases I find it difficult to = visualize the=20
exact setup that is being described.  A photograph or a = sketch would=20
be very helpful.

One way to do this is to start a = blog.  It's=20 easy to do
at:  http://blogger.com.  I started a = blog, just=20 to see how it
worked, and it only took a few minutes to add an=20 entry.  My "trial"
entry shows the AS-1 sensor:  http://seismoedu.blogspot.com/

I'm=20 sure there are other posting options as=20 = well.

Cheers,
John


_________________________________= _________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email = PSN-L-REQUEST@............... =20 with
the body of the message (first line only): unsubscribe
See = http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: A rough magnetic axis/pivot setup of the crossed rod variety From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 11:58:32 -0700 Hi all, I put up a web page of Dr. Randall Peters magnetic axis/pivot thought and that of Chris Chapmans crossed cylinders/rods pivot suggested idea. The magnet/s involved are those from Forcefield.com, and are of the polarity where the poles are through the rod diameter; and not at the ends of the rod; which is much more common. All in all, it really seems initally VERY interesting, from what little I've seen. The web page will text more observations and possiblities. One main point is that it appears that the mass weight can possibly exceed over 1.5 pounds...and the boom length for the natural period could be easily lengthened. I'd think it would best serve along the "hanging mass" orientation for a horizontal sensing unit; but, it could also be possible to lessen the mass weight to accomodate a vertical sensing unit. http://home.earthlink.net/~meredithlamb/magneticaxispivot/ Meredith Lamb
Hi all,
 
I put up a web page of Dr. Randall Peters magnetic axis/pivot thought and that of Chris
Chapmans crossed cylinders/rods pivot suggested idea. 
 
The magnet/s involved are those from Forcefield.com, and are of the polarity where
the poles are through the rod diameter; and not at the ends of the rod; which is much
more common.
 
All in all, it really seems initally VERY interesting, from what little I've seen.  The web
page will text more observations and possiblities.  One main point is that it appears
that the mass weight can possibly exceed over 1.5 pounds...and the boom length for
the natural period could be easily lengthened.   I'd think it would best serve along the
"hanging mass" orientation for a horizontal sensing unit; but, it could also be possible
to lessen the mass weight to accomodate a vertical sensing unit.
 
 
Meredith Lamb
 
 
Subject: possible vertical using magnets? From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 14:40:43 -0500 Kay, We know how you feel, but here's one more 'drinnk from the firehose'. We're 'on a roll', looks like. Meredith, like yourself, I saw the need to somehow communicate pictures; so I've placed one on my webpage at: http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif Anybody know instinctively if it's fatally flawed? I know Chris you don't like 'knife edges'. Maybe they're not as bad with load reduction by the pulling shown here. What about your thoughts, Charles, since I like your idea? And Keith, we're not opposed at all to what you've mentioned. I wrote a paper on the pendulum that moves in a way you'd like. Check out the pages that result if you type 'rattle in Seattle' into Google. I wouldn't be surprised if my 1988 paper "Chaotic motion from support constraints of a nondriven rigid spherical pendulum", Phys. Rev. A 38, 5352 prompted the commercial development that resulted in the 'oak and brass' pendulum that writes in sand and which recorded that Seattle earthquake. Randall Subject: Re: possible vertical using magnets? From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 13:13:50 -0700 Randall, Yes, its fatally flawed.....the mass will always go down in that setup....it has no where else to go (sorry). I'd think; putting the spring in back of the pivot, with the spring attachment above the pivot (upright metal fixture holder on the boom itself) would make it more workable (per your drawing). My hard drive and crossed rod pivot vertical experiment is somewhat similar. There the spring is in back of the pivot, but does go down at a slant. I can't go past the vertical point of the pivot, without it going "bonk" down. I can get up to about 1/4" away from the pivot for ~ a 2.5s period that "seems" fairly time stable. Going closer can extend the period (once it hit 11s); but, alas, it was just too unstable over time. Meredith Lamb On Nov 9, 2007 12:40 PM, Randall Peters wrote: > Kay, > We know how you feel, but here's one more 'drinnk from the firehose'. > We're 'on a roll', looks like. > Meredith, like yourself, I saw the need to somehow communicate pictures; > so I've placed one on my webpage at: > http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif > > Anybody know instinctively if it's fatally flawed? I know Chris you don't > like 'knife edges'. Maybe they're not as bad with load reduction by the > pulling shown here. What about your thoughts, Charles, since I like your > idea? > > And Keith, we're not opposed at all to what you've mentioned. I wrote a > paper on the pendulum that moves in a way you'd like. Check out the pages > that result if you type 'rattle in Seattle' into Google. I wouldn't be > surprised if my > 1988 paper "Chaotic motion from support constraints of a nondriven rigid > spherical pendulum", Phys. Rev. A 38, 5352 > prompted the commercial development that resulted in the 'oak and brass' > pendulum that writes in sand and which recorded that Seattle earthquake. > > Randall > >
Randall,
 
Yes, its fatally flawed.....the mass will always go down in that setup....it has no
where else to go (sorry).  I'd think; putting the spring in back of the pivot, with the
spring attachment above the pivot (upright metal fixture holder on the boom itself)
would make it more workable (per your drawing). 
 
My hard drive and crossed rod pivot vertical experiment is somewhat similar.  There the
spring is in back of the pivot, but does go down at a slant.  I can't go past the
vertical point of the pivot, without it going "bonk" down.  I can get up to about
1/4" away from the pivot for ~ a 2.5s period that "seems" fairly time stable.  Going
closer can extend the period (once it hit 11s); but, alas, it was just too unstable
over time.
 
Meredith Lamb

On Nov 9, 2007 12:40 PM, Randall Peters <PETERS_RD@..........> wrote:
Kay,
   We know how you feel, but here's one more  'drinnk from the firehose'.  We're 'on a roll', looks like.
Meredith, like yourself, I saw the need to somehow communicate pictures; so I've placed one on my webpage at:
http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif

Anybody know instinctively if it's fatally flawed?  I know Chris you don't like 'knife edges'.  Maybe they're not as bad with load reduction by the pulling shown here.  What about your thoughts, Charles, since I like your idea?

And Keith, we're not opposed at all to what you've mentioned.  I wrote a paper on the pendulum that moves in a way you'd like.  Check out the pages that result if you type 'rattle in Seattle' into Google.  I wouldn't be surprised if my
1988 paper "Chaotic motion from support constraints of a nondriven rigid spherical pendulum", Phys. Rev. A 38, 5352
prompted the commercial development that resulted in the 'oak and brass' pendulum that writes in sand and which recorded that Seattle earthquake.

Randall


Subject: Re: possible vertical using magnets? From: "Les LaZar" llazar@.................. Date: Fri, 9 Nov 2007 13:09:27 -0800 Randall, Your illustration is most informative, but the details of the pivot/axis are unclear. How are the magnets oriented with respect to the blade and what purpose do they serve? Les ----- Original Message ----- From: "Randall Peters" To: Sent: Friday, November 09, 2007 11:40 AM Subject: possible vertical using magnets? > Kay, > We know how you feel, but here's one more 'drinnk from the firehose'. > We're 'on a roll', looks like. > Meredith, like yourself, I saw the need to somehow communicate pictures; > so I've placed one on my webpage at: > http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif > > Anybody know instinctively if it's fatally flawed? I know Chris you don't > like 'knife edges'. Maybe they're not as bad with load reduction by the > pulling shown here. What about your thoughts, Charles, since I like your > idea? > > And Keith, we're not opposed at all to what you've mentioned. I wrote a > paper on the pendulum that moves in a way you'd like. Check out the pages > that result if you type 'rattle in Seattle' into Google. I wouldn't be > surprised if my > 1988 paper "Chaotic motion from support constraints of a nondriven rigid > spherical pendulum", Phys. Rev. A 38, 5352 > prompted the commercial development that resulted in the 'oak and brass' > pendulum that writes in sand and which recorded that Seattle earthquake. > > Randall > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: John Lahr johnjan@........ Date: Fri, 09 Nov 2007 13:53:04 -0800 Hi Jerry, I'm not advocating switching from E-mail to a blog, but simply using the blog as a convenient means to post images with captions. Words do not do justice to many of the things people are doing. A blog is just one of many possible ways to share graphics. Cheers, John At 07:46 AM 11/9/2007, you wrote: >I agree that visualization is VERY difficult sometimes, but I >hesitate creating a separate blog since it might water down the >discussions here. People might move to the blogs instead of here >and some might be left out of the comments. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 16:25:15 -0600 I know that you didn't, John. I was just afraid that a separate thread or comments might start on a blog that would not be read by some. I am in TOTAL agreement that we need to exchange drawings and photos when possible. Regards, Jerry Hi Jerry, I'm not advocating switching from E-mail to a blog, but simply using the blog as a convenient means to post images with captions. Words do not do justice to many of the things people are doing. A blog is just one of many possible ways to share graphics. Cheers, John At 07:46 AM 11/9/2007, you wrote: >I agree that visualization is VERY difficult sometimes, but I >hesitate creating a separate blog since it might water down the >discussions here. People might move to the blogs instead of here >and some might be left out of the comments. __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
I know that you didn't, John.  I was just afraid that a = separate=20 thread or comments might start on a blog that would not be read by=20 some.  I am in TOTAL agreement that we need to exchange drawings = and photos=20 when possible.
Regards,
Jerry
 
 
Hi Jerry,

I'm not advocating = switching from=20 E-mail to a blog, but simply using
the blog as a convenient means to = post=20 images with captions.  Words
do not do justice to many of the = things=20 people are doing.  A blog is
just one of  many possible = ways to=20 share graphics.

Cheers,
John

At 07:46 AM 11/9/2007, you = wrote:
>I agree that visualization is VERY difficult sometimes, = but I=20
>hesitate creating a separate blog since it might water down the=20
>discussions here.  People might move to the blogs instead = of here=20
>and some might be left out of the=20 comments.


____________________________________________________= ______

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: the design isn't fatally flawed From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 17:51:46 -0500 Meredith, I'm sorry to disagree with your claim that the idea I posted is fatally flawed.. I just assembled a prototype that does work. Pictures have been posted on the same site previously referenced.. The 'edge' is not the hard tungsten carbide that Charles recommended; I used an ordinary razor blade. The Q is not great, but you can see there are steel shavings still on the magnets. Also the lever arm needs to be longer than what I've used (part extending down from the magnets) to get a longer period with a bigger mass. At present, trying to lengthen substantially beyond about 1/2 s pulls the blade off the magnets. The reason the mass doesn't 'go down' to a non-operational state as you expected is because of the magnets' force on the blade; i.e., it is not resting at the center of the magnets. Randall Subject: Re: More productive exchange of ideas with graphics? From: dave dalex@............ Date: Fri, 09 Nov 2007 14:53:52 -0800 what about going to a yahoo account with a place for pictures. dave John Lahr wrote: > Hi Jerry, > > I'm not advocating switching from E-mail to a blog, but simply using the > blog as a convenient means to post images with captions. Words do not > do justice to many of the things people are doing. A blog is just one > of many possible ways to share graphics. > > Cheers, > John > > At 07:46 AM 11/9/2007, you wrote: > >> I agree that visualization is VERY difficult sometimes, but I hesitate >> creating a separate blog since it might water down the discussions >> here. People might move to the blogs instead of here and some might >> be left out of the comments. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: A rough magnetic axis/pivot setup of the crossed rod variety From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 15:55:19 -0700 Hi all, Interesting day! I added acouple shaft couplers to the end of the steel rod, and the magnetic repelling effect of such; was to force it to laterally center between the magnets. The effect is stronger laterally than with the steel rod going up and down the length of the magnets (per the picture/s)....but now, the overall magnetic fields are indeed tending to keep the axis/pivot into one centralized location. The magnets poles where the steel rod sits on, are of the same polarity in the new picture of such; but it works regardless of the top of the magnets N or S polarity See: http://home.earthlink.net/~meredithlamb/magneticaxispivot/ This is all just a experimental axis/pivot. There could very likely be problems that may end up religating it to the overflowing failure bin. Meredith Lamb
Hi all,
 
Interesting day!  I added acouple shaft couplers to the end of the steel rod, and the
magnetic repelling effect of such; was to force it to laterally center between the magnets.
The effect is stronger laterally than with the steel rod going up and down the length of
the magnets (per the picture/s)....but now, the overall magnetic fields are indeed tending
to keep the axis/pivot into one centralized location.  
 
The magnets poles where the steel rod sits on, are of the same polarity in the new
picture of such; but it works regardless of the top of the magnets N or S polarity   See:
 
 
This is all just a experimental axis/pivot.  There could very likely be problems that may
end up religating it to the overflowing failure bin.
 
Meredith Lamb
 
 
 
Subject: Re: Exchange of ideas with graphics From: Dave Nelson davenn@............... Date: Sat, 10 Nov 2007 09:56:23 +1100 Thanks John, I dont really care if some one uses their www site or a blog ..... after all its primary use will be to dislay the graphics in a very easy to access way As you discovered Kay using the ftp wouldnt be easy for everyone and Larry would need to give password permissions to ppl an added hassle Keep the main discussions on this list but give links to where ever else blog or www site for the graphics :) and all wil be happy I know I also have "fun" trying to understand what ppl are trying to describe and as John has proven its dead easy to create a blog, specially when compared to starting up a www site keep it going John and hope others do the same to share their pix If anyone really wants to share their pix without starting a blog or www site email me the pix and I will create pages on my site for them pand post links on the email list very happy to do that :) Cheers Dave N Sydney At 05:57 AM 10/11/2007, you wrote: >To all PSN folks, >Has anybody been able to send graphics to the PSN ftp site? When I ftp to >the site I am asked for account and password. . >I agree with Jerry (below) that I would worry about using John Lahr's blog >site INSTEAD of the PSN. But what about using it WITH the PSN email >system. That is, to upload a drawing to the blog and reference it with a >hyperlink to the blog site? >I look forward to hearing any further discussion on this important issue. >By the way, are there any other women amateur seismologists on this >list? How many of you guys have shared your hobby with your daughters? ;-) >Kay Wyatt -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.15.26/1119 - Release Date: 08/11/2007 5:55 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: the design isn't fatally flawed From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 16:00:26 -0700 Hi Randall, Yes...I admitted earlier in a email that it could work...I was wrong. Good deal on getting a model working! It will be interesting to keep informed of this one. Meredith Lamb On Nov 9, 2007 3:51 PM, Randall Peters wrote: > Meredith, > I'm sorry to disagree with your claim that the idea I posted is fatally > flawed.. > I just assembled a prototype that does work. Pictures have been posted on > the same site previously referenced.. > The 'edge' is not the hard tungsten carbide that Charles recommended; I > used an ordinary razor blade. > The Q is not great, but you can see there are steel shavings still on the > magnets. Also the lever arm needs to be > longer than what I've used (part extending down from the magnets) to get a > longer period with a bigger mass. At present, trying to lengthen > substantially beyond about 1/2 s pulls the blade off the magnets. > The reason the mass doesn't 'go down' to a non-operational state as you > expected is because of the magnets' force on the blade; i.e., it is not > resting at the center of the magnets. > Randall > >
Hi Randall,
 
Yes...I admitted earlier in a email that it could work...I was wrong.  Good deal on
getting a model working!  It will be interesting to keep informed of this one.
 
Meredith Lamb

On Nov 9, 2007 3:51 PM, Randall Peters <PETERS_RD@..........> wrote:
Meredith,
  I'm sorry to disagree with your claim that the idea I posted is fatally flawed..
I just assembled a prototype that does work.  Pictures have been posted on the same site previously referenced..
The 'edge' is not the hard tungsten carbide that Charles recommended; I used an ordinary razor blade.
The Q is not great, but you can see there are steel shavings still on the magnets.  Also the lever arm needs to be
longer than what I've used (part extending down from the magnets) to get a longer period with a bigger mass.  At present, trying to lengthen substantially beyond  about 1/2 s pulls the blade off the magnets.
  The reason the mass doesn't 'go down' to a non-operational state as you expected is because of the magnets' force on the blade; i.e., it is not resting at the center of the magnets.
 Randall


Subject: Re: the design isn't fatally flawed From: tchannel1@............ Date: Fri, 9 Nov 2007 16:21:25 -0700 Randall, Please,Where are the pictures posted? Thanks,=20 Ted ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Friday, November 09, 2007 4:00 PM Subject: Re: the design isn't fatally flawed Hi Randall, Yes...I admitted earlier in a email that it could work...I was wrong. = Good deal on getting a model working! It will be interesting to keep informed of = this one. Meredith Lamb On Nov 9, 2007 3:51 PM, Randall Peters wrote: Meredith, I'm sorry to disagree with your claim that the idea I posted is = fatally flawed.. I just assembled a prototype that does work. Pictures have been = posted on the same site previously referenced..=20 The 'edge' is not the hard tungsten carbide that Charles = recommended; I used an ordinary razor blade. The Q is not great, but you can see there are steel shavings still = on the magnets. Also the lever arm needs to be=20 longer than what I've used (part extending down from the magnets) to = get a longer period with a bigger mass. At present, trying to lengthen = substantially beyond about 1/2 s pulls the blade off the magnets. The reason the mass doesn't 'go down' to a non-operational state = as you expected is because of the magnets' force on the blade; i.e., it = is not resting at the center of the magnets. Randall
Randall,   Please,Where are = the pictures=20 posted?  Thanks,
Ted
----- Original Message -----
From:=20 meredith lamb
Sent: Friday, November 09, 2007 = 4:00=20 PM
Subject: Re: the design isn't = fatally=20 flawed

Hi Randall,
 
Yes...I admitted earlier in a email that it could work...I was=20 wrong.  Good deal on
getting a model working!  It will be interesting to=20 keep informed of this one.
 
Meredith Lamb

On Nov 9, 2007 3:51 PM, Randall Peters <PETERS_RD@..........> = wrote:
Meredith,
 =20 I'm sorry to disagree with your claim that the idea I posted is = fatally=20 flawed..
I just assembled a prototype that does work. =  Pictures have=20 been posted on the same site previously referenced..
The 'edge' = is not=20 the hard tungsten carbide that Charles recommended; I used an = ordinary razor=20 blade.
The Q is not great, but you can see there are steel = shavings still=20 on the magnets.  Also the lever arm needs to be
longer than = what=20 I've used (part extending down from the magnets) to get a longer = period with=20 a bigger mass.  At present, trying to lengthen substantially = beyond=20  about 1/2 s pulls the blade off the magnets.
  The = reason the=20 mass doesn't 'go down' to a non-operational state as you expected is = because=20 of the magnets' force on the blade; i.e., it is not resting at the = center of=20 the magnets.
 Randall


Subject: Re: the design isn't fatally flawed From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 19:41:19 -0700 Randalls gif drawing of his vertical is at: http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif Randalls reference to a pendulum point tracing in sand, or, the "rattle in seattle" phrase is at: http://www.aps.org/publications/apsnews/200105/zero-gravity.cfm Meredith Lamb On Nov 9, 2007 4:21 PM, wrote: > Randall, Please,Where are the pictures posted? Thanks, > Ted > > ----- Original Message ----- > *From:* meredith lamb > *To:* psn-l@.............. > *Sent:* Friday, November 09, 2007 4:00 PM > *Subject:* Re: the design isn't fatally flawed > > Hi Randall, > > Yes...I admitted earlier in a email that it could work...I was wrong. > Good deal on > getting a model working! It will be interesting to keep informed of this > one. > > Meredith Lamb > > On Nov 9, 2007 3:51 PM, Randall Peters wrote: > > > Meredith, > > I'm sorry to disagree with your claim that the idea I posted is > > fatally flawed.. > > I just assembled a prototype that does work. Pictures have been posted > > on the same site previously referenced.. > > The 'edge' is not the hard tungsten carbide that Charles recommended; I > > used an ordinary razor blade. > > The Q is not great, but you can see there are steel shavings still on > > the magnets. Also the lever arm needs to be > > longer than what I've used (part extending down from the magnets) to get > > a longer period with a bigger mass. At present, trying to lengthen > > substantially beyond about 1/2 s pulls the blade off the magnets. > > The reason the mass doesn't 'go down' to a non-operational state as > > you expected is because of the magnets' force on the blade; i.e., it is > > not resting at the center of the magnets. > > Randall > > > > >
Randalls gif drawing of his vertical is at:
 
 
Randalls reference to a pendulum point tracing in sand, or, the
"rattle in seattle" phrase is at:
 
 
Meredith Lamb

On Nov 9, 2007 4:21 PM, <tchannel1@............> wrote:
Randall,   Please,Where are the pictures posted?  Thanks,
Ted
----- Original Message -----
Sent: Friday, November 09, 2007 4:00 PM
Subject: Re: the design isn't fatally flawed

Hi Randall,
 
Yes...I admitted earlier in a email that it could work...I was wrong.  Good deal on
getting a model working!  It will be interesting to keep informed of this one.
 
Meredith Lamb

On Nov 9, 2007 3:51 PM, Randall Peters <PETERS_RD@..........> wrote:
Meredith,
  I'm sorry to disagree with your claim that the idea I posted is fatally flawed..
I just assembled a prototype that does work.  Pictures have been posted on the same site previously referenced..
The 'edge' is not the hard tungsten carbide that Charles recommended; I used an ordinary razor blade.
The Q is not great, but you can see there are steel shavings still on the magnets.  Also the lever arm needs to be
longer than what I've used (part extending down from the magnets) to get a longer period with a bigger mass.  At present, trying to lengthen substantially beyond  about 1/2 s pulls the blade off the magnets.
  The reason the mass doesn't 'go down' to a non-operational state as you expected is because of the magnets' force on the blade; i.e., it is not resting at the center of the magnets.
 Randall



Subject: OmniDirectional Free Hanging Pendulum and Voltage VS Current sensors From: "Geoff" gmvoeth@........... Date: Sat, 10 Nov 2007 06:17:15 -0700 Hello All you PSN Peoples; Please Referr to the following image. It is much like a product called Magnasee that allowes one to actually see the magnetic tracks on a recording tape. It is referred to as a magnetic developer sort of like developing an old photography film. This image is showing a horizontal EQ motion developer using something like a kids toy. Such visualizations will help one understand the reality of what you are dealing with. http://www.aps.org:80/publications/apsnews/200105/zero-gravity.cfm This image from one of your other posts is a visible indicator that a free hanging pendulum with a nondirectional sensor may very well give the best picture of all X or Y sensors. Otherwise you need to sum both X + Y with a summation amp and that will double your effort. Can someone show me the best way to use a single simple pendulum with the magnet as a mass and and one or two coils as the receiver ?? I still like no matter what you say the magnet as the pendulous mass. I also know from past experience if you want to deal with voltages you use vacuum tubes and if you want to deal with current you use semiconductors so why do you need so many coils in a sensor coil ?? Today we use almost always semiconductors and I think a single loop of very heavy wire may be better for semiconductors ( IC OP AMPS ) then having multiple turn coils ??? can anyone please address this idea too ?? I am pretty much a laymen but through the past many years been exposed to many different general ideas of physics. Regards; Geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: HEy all you Eggheads, Please Tell me something I dont Know From: "Geoff" gmvoeth@........... Date: Sat, 10 Nov 2007 07:56:54 -0700 Hi All You PSN Folks; Why Every Time I Send A message to The PSN group do I get this error message ?? Any ONE know please reply to me personally at gmvoeth hotmail.com gmvoeth yahoo.com gmvoeth gmail.com Just add the at sign. any of these will do. I do not even know anyone named dhidayat hotmail.com Regards; geoff ************* BELOW MESSAGE *********** Reporting-MTA: dns;imc2-s4.hotmail.com Received-From-MTA: dns;wim1-s4.hotmail.com Arrival-Date: Sat, 10 Nov 2007 06:09:39 GMT Final-Recipient: rfc822;dhidayat@........... Action: failed Status: 5.5.0 Diagnostic-Code: smtp;550 Requested action not taken: mailbox unavailable __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: pendulum that generated 'rattle in seattle' From: Randall Peters PETERS_RD@.......... Date: Sat, 10 Nov 2007 10:21:21 -0500 Geoff, The pendulum responsible for the now-famous picture you and Meredith mention (and give the American Physical Society-hosted sebsite) is not like the dangling pendulum we've been discussing. As you noted, it is a 'toy'-version of the one that I studied (responsible for the aforementioned article on chaos) and which has for years been used to generate beautiful art-pieces. A picture of that pendulum which I built (while still at Texas Tech University) and which is here in the Mercer physics department is to be found at http://physics.mercer.edu/Science_Art/bowling_ball.htm Also on this website are some of the myriad traces that have been produced with the pendulum. Art-folks love these because of their 'life-like' properties--no two exactly the same (quite unlike computer generated patterns). The bowling ball is supported by a pipe on one end, the other end of which is connected to a universal joint (off a toyota pickup if I remember correctly). Because of this U-joint, the x-y axes are coupled, giving rise to a very large number of different patterns during free decay. The moments of inertia in the two axes are adjustable to provide additional control that assists the near infinity of possible results. In the absence of friction, this instrument would display what's called Hamiltonian chaos. The sensitive dependence on initial conditions (essence of the butterfly effect) means that long term prediction (just like the weather) is unpredictable. There are two capacitive sensors that map the motion of the bowling ball, one in each of the perpendicular axes. The output from the amplified signals is fed to an x-y (analog recorder) that with a ball-point pen generates the images on ordinary paper. I have done a lot of chaos research in the last 15 years. The chaotic pendulum that I designed and which is online here at Mercer (when my colleague Matt Marone gets it back operational after our move to the new building) is at http://physics.mercer.edu/PENDULUM/ This pendulum can be controlled from anywhere in the world over the internet when operational. The parameter that the user can adjust is the frequency of the drive. The pendulum's motion is monitored by one of my SDC sensors functioning as a velocity detector. An aluminum disk rotates with the pendulum between rare-earth magnets positioned on either side, which are on the end of a bending cantilever. The output (velocity) is integrated with a 'leaky' integrator to give the position. Largely because of my pendulum chaos studies I was asked and wrote an article on " math methods used by physicists to study chaos" for the 10th Ed. of the McGraw Hill Encyclopedia of Science and Technology. I'm sure that some readers will note the prominence of other authors in the chaos section of the encylopedia (such as the creator of the butterfly effect, Ed Lorenz) and then will say, "but who's this guy, Peters?". You ask, Geoff, 'why use multiple turn coils for the Faraday-law sensor. The answer is resident within the statement of his law (generated, in the minds of most, by the greatest experimentalist who ever lived). Faraday's law states that the voltage generated within the wire (historically called the electromotive force (emf) even though voltage is not a force) is proportional to the number of turns of the coil times the time rate of change of the magnetic flux passing through the coil. Thus no matter how your amplifier is built (solid state or vacuum tubes) the signal will be greater the larger number of turns you can wind within the constraints of space limitations borne of wire size and increased resistance that results when the wire gets too small trying to put more turns into a given place. Randall Subject: Re: OmniDirectional Free Hanging Pendulum and Voltage VS From: John Lahr johnjan@........ Date: Sat, 10 Nov 2007 08:00:36 -0800 Nice picture of the sand seismoscope. The following explanation is not correct, however: "The "flower" in the center records the surface movements associated with the higher frequency waves that arrived first. The outer larger amplitude oscillations record the lower frequency waves that arrived later. The lines from the largest pattern are interrupted by the rose pattern. The rose is probably due to the earthquake vibrations while the large-scale pattern was human generated some time earlier. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: magnetic axis/pivot/crossed rod From: Randall Peters PETERS_RD@.......... Date: Sat, 10 Nov 2007 11:14:22 -0500 Meredith, What you've done is VERY interesting. Am I correct in assuming that your latest test (1.5 lbs oscillating 50 minutes) was with the aluminum rod hanging down and swinging from the stationary steel plate, with the 1.5 lb weight at the bottom? If so, how far below the axis was the weight. The moment of inertia is an important issue in the decay time, so I would really like to know this number to try and assess the relative importance of air damping compared to the internal friction associated with your axis. Randall Subject: Re: magnetic axis/pivot/crossed rod From: "meredith lamb" paleoartifact@......... Date: Sat, 10 Nov 2007 11:03:31 -0700 Hi Randall and all, Yes, I put the steel block upside down and clamped it to the edge of a table; with of course the magnets underneath the steel block (and moved the magnets to accomodate a clamp). I put up a third picture and text at the web site in relation to this. See: http://home.earthlink.net/~meredithlamb/magneticaxispivot/ The distance between the center of the pivot and the center of (another steel block) is ~17.625", with a natural period of ~1.34s. The web page distance number is not correct. Of course the surface hardness of the gold plated neo magnets and the surface of the unhardened steel rod are not very good. One could rightly say the whole thing is kind of a curio type experiment, and of little long term operational value...which it is presently. It might be possible to "adapt" some kind of cutoff small section of harder magnetic steel pipe that fits the outer contact portion diameter of the neo magnets to provide a harder contact surface there....while also getting a harder pivot rod. If one compares say a "standard" crossed rod that simply gravitational rests atop the rods, and this magnetic attachment; the standard crossed rods can freely oscillate up to about ~ 4 times longer (per past home brew experiments). However, the magnetic centering aspect of this present unit is of great interest as it can roughly ~"positon zero" itself, whereas the standard non-magnetic crossed rod/cylinder unit can't self adjust, without perhaps resorting to again configuring some kind of magnetic attraction/repulsion system on the "standard" configuration. Obviously I'am interested in the crossed rod pivot approach even though it has its problems of positional zeroing use. I note that per the first web site picture, where the boom goes up, it could also go down through the steel block hole; with the mass hanging underneath. I suppose that route would be even better to manipulate any mechanical or magnetic centering aspects. I've not yet tried any kind of vertical with any kind of spring add on. Can only roughly surmise the mass weight would need to "whatever" the spring and pivot can take of course. If one stands the 1-2-3" block on its 2x1" thick side per the first view (with a base plate slight tilt)....then you can likely get another horizontal sensing route; but likely the mass weight would again be alot less than 2 pounds of course. Yes...there is a variety of possiblities of a number of pivot orientation routes with this....but whether they are proven practical (with improvements) remains to be seen. Meredith Lamb On Nov 10, 2007 9:14 AM, Randall Peters wrote: > Meredith, > What you've done is VERY interesting. Am I correct in assuming that > your latest test (1.5 lbs > oscillating 50 minutes) was with the aluminum rod hanging down and > swinging from the stationary steel plate, > with the 1.5 lb weight at the bottom? If so, how far below the axis was > the weight. The moment of inertia is an > important issue in the decay time, so I would really like to know this > number to try and assess the > relative importance of air damping compared to the internal friction > associated with your axis. > > Randall >
Hi Randall and all,
 
Yes, I put the steel block upside down and clamped it to the edge of a table; with of
course the magnets underneath the steel block (and moved the magnets to accomodate
a clamp).  I put up a third picture and text at the web site in relation to this.  See:
 
The distance between the center of the pivot and the center of (another steel block) is
~17.625", with a natural period of ~1.34s.  The web page distance number is not correct.
 
Of course the surface hardness of the gold plated neo magnets and the surface of the unhardened
steel rod are not very good.  One could rightly say the whole thing is kind of a curio type
experiment, and of little long term operational value...which it is presently.  It might be
possible to "adapt" some kind of cutoff small section of harder magnetic steel pipe that fits the outer
contact portion diameter of the neo magnets to provide a harder contact surface there....while
also getting a harder pivot rod.
 
If one compares say a "standard" crossed rod that simply gravitational rests atop the rods, and this
magnetic attachment; the standard crossed rods can freely oscillate up to about ~ 4 times
longer (per past home brew experiments).   However, the magnetic centering aspect of
this present unit is of great interest as it can roughly ~"positon zero" itself, whereas the
standard non-magnetic crossed rod/cylinder unit can't self adjust, without perhaps resorting to
again configuring some kind of magnetic attraction/repulsion system on the "standard"
configuration.  Obviously I'am interested in the crossed rod pivot approach even though it
has its problems of positional zeroing use. 
 
I note that per the first web site picture, where the boom goes up, it could also go down
through the steel block hole; with the mass hanging underneath.  I suppose that route
would be even better to manipulate any mechanical or magnetic centering aspects. 
 
I've not yet tried any kind of vertical with any kind of spring add on.  Can only roughly
surmise the mass weight would need to "whatever" the spring and pivot can take of
course.
 
If one stands the 1-2-3" block on its 2x1" thick side per the first view (with a base
plate slight tilt)....then you can likely get another horizontal sensing route; but likely
the mass weight would again be alot less than 2 pounds of course.  Yes...there is
a variety of possiblities of a number of pivot orientation routes with this....but whether
they are proven practical (with improvements) remains to be seen.
 
Meredith Lamb   


 
On Nov 10, 2007 9:14 AM, Randall Peters <PETERS_RD@..........> wrote:
Meredith,
   What you've done is VERY interesting.  Am I correct in assuming that your latest test ( 1.5 lbs
oscillating 50 minutes) was with the aluminum rod hanging down and swinging from the stationary steel plate,
with the 1.5 lb weight at the bottom?  If so, how far below the axis was the weight.  The moment of inertia is an
important issue in the decay time, so I would really like to know this number to try and assess the
relative importance of air damping compared to the  internal friction associated with your axis.

 Randall

Subject: map of seismic risk in East Africa? From: "David Saum" DSaum@............ Date: Sat, 10 Nov 2007 16:00:53 -0500 A friend of mine in Tanzania asks > are you aware of anyone on the web who might "publish" or know > of a mechanism that would provide some sort of probability or at least > risk assessment of earthquake frequencey and/or magnitude? For example, we > know that a road built near Ol Donyo Lengai would be subject to higher > risk than a road built in Dar--but is anybody using data to quantify this? Can anyone provide a reference for this? Thanks in advance, Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: map of seismic risk in East Africa? From: Angel sismos@.............. Date: Sat, 10 Nov 2007 21:10:55 +0000 Hello David, Much of this work in Central America is sponsored by NORSAR http://www.norsar.no/seismology/ Angel Saturday, November 10, 2007, 9:00:53 PM, you wrote: > A friend of mine in Tanzania asks >> are you aware of anyone on the web who might "publish" or know >> of a mechanism that would provide some sort of probability or at least >> risk assessment of earthquake frequencey and/or magnitude? For example, we >> know that a road built near Ol Donyo Lengai would be subject to higher >> risk than a road built in Dar--but is anybody using data to quantify this? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: pendulum suspensions From: holmstro@.......... Date: Sat, 10 Nov 2007 13:22:28 -0800 (PST) Hello, This is my first post to the list. I am Bob Holmström, Editor of the Horological Science Newsletter (NAWCC Chapter 161). Pendulum suspensions are of great interest to those interested in precision time keeping. Perhaps there is some use discussing what clockmakers have learned even though a clock pendulum needs to move constantly over a much larger angle than the devices discussed here. But first, since Dr. Peters suggestion to use a magnet suspended carbide ball is what prompted my response, I want to discuss a prior experiment: Marcel Bétrisey, a Swiss artist who has created many clocks and Foucault pendulums from "found materials", has experimented with a Foucault pendulum suspended from a ball attracted to a high strength magnet. He found that the motion was not "homogenious", in that the amplitude of the motion and the rate of change of the direction of motion had significent variations. Anyone who has attemped to build build an accurate Foucault pendulum can attest to the fact that the suspension design is critical and even then error correction devices such as Charon rings or Eddy current damping are required to get anthing close to accurate motion. Unfortunately the error correction devices add there own errors! Kammerling Onnes (1890's) used a crossed knife edge suspension without error correction for a Foucault pendulum and achieved some of the most accurate results ever obtained. Marcel's best results have been with pendulums suspended from guitar wire located by a stack of close fitting watch jewels in a collet. Some of Marcel's work can be seen at www.foucault.ch and www.betrisey.ch For a real treat on the interaction of art, science, and horology see his radiometric pendulums. re clock pendulum suspensions: Most pendulums hang from flexures, including very precise clocks such as those constructed by Shortt and Fedchenko. The connections between the flexure and its support and pendulum are very important - simple clamping can be problematic - Shortt and Fedchenko used spring machined from blocks (i.e. thick ends) with great success. Modern edm techniques make this type of spring relatively easy to construct. Gravity wave detection pendulums use similiar suspensions constructed from low loss materials such as indium. True knife edge suspensions probably do not exist - contact forces and irregular contact geometry produce something less than ideal. Much better results are obtained with edges shaped to a small radius that can be obtained by lapping with an appropriate jig or by more modern edm methods. One test of a pendulum suspension for a clock is to see if it shows true "circular error" (a horological term probably best expressed as period error due to the fact that a pendulum is not truely isochronus - i.e. the period varies with amplitude). It is very difficult to construct a pendulum that agrees well with theoretical predictions. Plotting period versus amplitude squared makes extrapolating the data to zero amplitude much simpler than the traditional form of plot and it shows the errors quite readily. The idea was suggested by Stroud and Matthews, "Period of a rigid pendulum pivoting on flattened knife edges" Physics Education, Volume 22 (1987) pages 170 - 173. I intend to evaluate Chris Chapmen's crossed roller suspension and Meredith Lamb's hard disc id suspension when I return home in a couple of weeks. The best pendulum suspension results that I have obtained so far are with an air bearing suspended pendulum. The pendulum was suspended from both ends of a rod passing through a porus graphite air bearing, first with magnets controling side to side drift and then air bearings on the ends also. Some results and photos of the setup are at http://www.hsn161.com/air.html Perhaps not the most practical - the air bearings are not cheap and a continuly running air compressor is a bit annoying!) Note: John Harrison used a third method to control end to end drift and to reduce friction in his H1 chronometer e.g. he used a small fiber from each end of the rod to a fixed support - in addition the rod was supported on "anti-friction" rollers (imagine segments of two large wheels with the shaft resting at the intersection of their radii at each end of the shaft.) Bob Holmström __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Paper-Mate -Lubriglide From: tchannel1@............ Date: Sat, 10 Nov 2007 15:06:15 -0700 Hi All, I am now testing the PMG Paper mate Lubriglide, SENSOR, This = took well over a hour and I did not have to go to the hardware store = once. My camera battery is down, but if someone would like some picts just = email me. I know a pict is worth a thousand words, but I will try to = describe it. 1. I use a 1/8" x 36" wood dowel, taped a Paper-Mate pen refill to it, = ball end up. 2. I use a camera tripod, and attached a rare earth magnet to the = handle of the tripod, (the tilting handle which is steel). Using the = crank on the tripod I can raise and lower the dowel. 3. I found a small steel nut which I could thread onto the dowel, a = washer on top of the nut, then a larger hex nut, about 1/4" 20 thread. = on top of the washer. This created a base for two bar magnets,(the washer) and a shoulder for = the ends of the magnets.(the larger nut) So left to right=3D = magnet+nut+magnet The small nut and washer supports the magnets so = they don't fall down the dowel. By threading the small nut and washer up and down the dowel you change = the magnets height. 4. I used two small bar magnets, 1/4" x 1/2" x 1"=20 I turned the crank on the tripod lowering the two magnets to within = 1/16" above the coil. ( Coil laying flat, dowel passing thru center = hole, of the coil spool, two bar magnets, left and right=3D N and S, = just above the plastic coil spool.) This also lowered the end of the = dowel deeper into the oil. 5. I laid the doe nut shaped coil, laying flat, on top of a small = plastic cup, filled will oil as a damper. 6. The dowel passes thru the coil spool and extends into the oil. I = did not use a paddle on the dowel, it seems to damp well by adding more = oil. The coil I got from friend Jerry, which is 6000? turns of 28ga. Using Larry's board and the DataQ, its producing a very nice signal. I = placed the whole thing in a 5 gallon bucket and covered the top of the = bucket with towels to isolate most of the parts, from air currents. = The ball point pen and the top 20" of the dowel are exposed. The signal looks strong, I turned the gain on AmaSeis down to 2, which = is about what I use on other sensors. Not a high tech sensor, but I am going to record some earthquakes and = see how they look.........if we get some earthquakes. Thanks everyone. Ted
Hi All,  I am now testing the = PMG  Paper=20 mate Lubriglide, SENSOR,   This took well over a hour and I = did not=20 have to go to the hardware store once.
 
My camera battery is down, but if = someone would=20 like some picts just email me.  I know a pict is worth a thousand = words,=20 but I will try to describe it.
 
1.  I use a 1/8" x 36" wood dowel, = taped a=20 Paper-Mate pen refill to it, ball end up.
2.  I use a camera tripod, and = attached a rare=20 earth magnet to the handle of the tripod, (the tilting handle which = is=20 steel). Using the crank on the tripod I can raise and lower the=20 dowel.
3.  I found a small steel nut = which I could=20 thread onto the dowel, a washer on top of the nut, then a larger hex = nut, about=20 1/4" 20 thread. on top of the washer.
 This created a base for two bar = magnets,(the=20 washer) and a shoulder for the ends of the  magnets.(the = larger=20 nut)  So left to right=3D magnet+nut+magnet   The small = nut and=20 washer supports the magnets so they don't fall down the = dowel.
By threading the small nut and washer = up and down=20 the dowel you change the magnets height.
 
 4. I used two small bar magnets, = 1/4" x 1/2"=20 x 1" 
 
 I turned the crank on the tripod = lowering the=20 two magnets to within 1/16" above the coil. ( Coil laying flat, = dowel=20 passing thru center hole, of the coil spool, two bar magnets, left = and=20 right=3D N and S, just above the plastic coil spool.)   This = also=20 lowered the end of the dowel deeper into the oil.
 
5.  I laid the  doe nut = shaped coil,=20 laying flat, on top of a small plastic cup, filled will oil as a=20 damper.
 
6.  The dowel passes thru the coil = spool and=20 extends into the oil.  I did not use a paddle on the dowel, it = seems to=20 damp well by adding more oil.
 
The coil I got from friend Jerry, which = is 6000?=20 turns of 28ga.
 
 
Using Larry's board and the DataQ, its = producing a=20 very nice signal.   I placed the whole thing in a 5 gallon = bucket and=20 covered the top of the bucket with towels to isolate most of the parts, = from air=20 currents.   The ball point pen and the top 20" of the dowel = are=20 exposed.
 
The signal looks strong, I turned the = gain on=20 AmaSeis down to 2, which is about what I use on other = sensors.
 
Not a high tech sensor, but I am going = to record=20 some earthquakes and see how they look.........if we get some=20 earthquakes.
 
Thanks everyone.
Ted
Subject: Re: map of seismic risk in East Africa? From: John Lahr johnjan@........ Date: Sat, 10 Nov 2007 14:08:32 -0800 This is a good reference for global seismic hazard. http://www.seismo.ethz.ch/gshap/ The resolution may not be sufficient, however. This reference, which I haven't seen, is given: Midzi, V., Hlatywayo, D. J., Chapola, L. S., Kebede, F., Atakan, K., Lombe, D. K., Turyomurugyendo, G., & Tugume, F. A., 1999. Seismic hazard assessment in Eastern and Southern Africa, Annali di Geofisica, GSHAP Special Volume. John At 01:00 PM 11/10/2007, you wrote: >A friend of mine in Tanzania asks > > > are you aware of anyone on the web who might "publish" or know > > of a mechanism that would provide some sort of probability or at least > > risk assessment of earthquake frequencey and/or magnitude? For example, we > > know that a road built near Ol Donyo Lengai would be subject to higher > > risk than a road built in Dar--but is anybody using data to quantify this? > >Can anyone provide a reference for this? > >Thanks in advance, > >Dave > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: pendulum suspensions From: tchannel1@............ Date: Sat, 10 Nov 2007 15:14:10 -0700 Hi Bob, Thank you for this interesting input. and the wed links. Ted ----- Original Message ----- From: To: Cc: Sent: Saturday, November 10, 2007 2:22 PM Subject: pendulum suspensions > Hello, > > This is my first post to the list. I am Bob Holmström, Editor of the > Horological Science Newsletter (NAWCC Chapter 161). Pendulum suspensions > are of great interest to those interested in precision time keeping. > Perhaps there is some use discussing what clockmakers have learned even > though a clock pendulum needs to move constantly over a much larger angle > than the devices discussed here. > > But first, since Dr. Peters suggestion to use a magnet suspended carbide > ball is what prompted my response, I want to discuss a prior experiment: > > Marcel Bétrisey, a Swiss artist who has created many clocks and Foucault > pendulums from "found materials", has experimented with a Foucault > pendulum suspended from a ball attracted to a high strength magnet. He > found that the motion was not "homogenious", in that the amplitude of the > motion and the rate of change of the direction of motion had significent > variations. Anyone who has attemped to build build an accurate Foucault > pendulum can attest to the fact that the suspension design is critical and > even then error correction devices such as Charon rings or Eddy current > damping are required to get anthing close to accurate motion. > Unfortunately the error correction devices add there own errors! > Kammerling Onnes (1890's) used a crossed knife edge suspension without > error correction for a Foucault pendulum and achieved some of the most > accurate results ever obtained. Marcel's best results have been with > pendulums suspended from guitar wire located by a stack of close fitting > watch jewels in a collet. Some of Marcel's work can be seen at > www.foucault.ch and www.betrisey.ch For a real treat on the interaction > of art, science, and horology see his radiometric pendulums. > > re clock pendulum suspensions: Most pendulums hang from flexures, > including very precise clocks such as those constructed by Shortt and > Fedchenko. The connections between the flexure and its support and > pendulum are very important - simple clamping can be problematic - Shortt > and Fedchenko used spring machined from blocks (i.e. thick ends) with > great success. Modern edm techniques make this type of spring relatively > easy to construct. Gravity wave detection pendulums use similiar > suspensions constructed from low loss materials such as indium. > > True knife edge suspensions probably do not exist - contact forces and > irregular contact geometry produce something less than ideal. Much better > results are obtained with edges shaped to a small radius that can be > obtained by lapping with an appropriate jig or by more modern edm methods. > > One test of a pendulum suspension for a clock is to see if it shows true > "circular error" (a horological term probably best expressed as period > error due to the fact that a pendulum is not truely isochronus - i.e. the > period varies with amplitude). It is very difficult to construct a > pendulum that agrees well with theoretical predictions. Plotting period > versus amplitude squared makes extrapolating the data to zero amplitude > much simpler than the traditional form of plot and it shows the errors > quite readily. The idea was suggested by Stroud and Matthews, "Period of a > rigid pendulum pivoting on flattened knife edges" Physics Education, > Volume 22 (1987) pages 170 - 173. > > I intend to evaluate Chris Chapmen's crossed roller suspension and > Meredith Lamb's hard disc id suspension when I return home in a couple of > weeks. > > The best pendulum suspension results that I have obtained so far are with > an air bearing suspended pendulum. The pendulum was suspended from both > ends of a rod passing through a porus graphite air bearing, first with > magnets controling side to side drift and then air bearings on the ends > also. Some results and photos of the setup are at > http://www.hsn161.com/air.html Perhaps not the most practical - the air > bearings are not cheap and a continuly running air compressor is a bit > annoying!) > > Note: John Harrison used a third method to control end to end drift and to > reduce friction in his H1 chronometer e.g. he used a small fiber from each > end of the rod to a fixed support - in addition the rod was supported on > "anti-friction" rollers (imagine segments of two large wheels with the > shaft resting at the intersection of their radii at each end of the > shaft.) > > Bob Holmström > > > > > > > > > > > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Paper-Mate -Lubriglide From: ian ian@........... Date: Sat, 10 Nov 2007 22:19:34 +0000 I think a picture would definately help... Ian tchannel1@............ wrote: > Hi All, I am now testing the PMG Paper mate Lubriglide, SENSOR, > This took well over a hour and I did not have to go to the hardware > store once. > > My camera battery is down, but if someone would like some picts just > email me. I know a pict is worth a thousand words, but I will try to > describe it. > > 1. I use a 1/8" x 36" wood dowel, taped a Paper-Mate pen refill to > it, ball end up. > 2. I use a camera tripod, and attached a rare earth magnet to the > handle of the tripod, (the tilting handle which is steel). Using the > crank on the tripod I can raise and lower the dowel. > 3. I found a small steel nut which I could thread onto the dowel, a > washer on top of the nut, then a larger hex nut, about 1/4" 20 > thread. on top of the washer. > This created a base for two bar magnets,(the washer) and a shoulder > for the ends of the magnets.(the larger nut) So left to right= > magnet+nut+magnet The small nut and washer supports the magnets so > they don't fall down the dowel. > By threading the small nut and washer up and down the dowel you change > the magnets height. > > 4. I used two small bar magnets, 1/4" x 1/2" x 1" > > I turned the crank on the tripod lowering the two magnets to within > 1/16" above the coil. ( Coil laying flat, dowel passing thru center > hole, of the coil spool, two bar magnets, left and right= N and S, > just above the plastic coil spool.) This also lowered the end of the > dowel deeper into the oil. > > 5. I laid the doe nut shaped coil, laying flat, on top of a small > plastic cup, filled will oil as a damper. > > 6. The dowel passes thru the coil spool and extends into the oil. I > did not use a paddle on the dowel, it seems to damp well by adding > more oil. > > The coil I got from friend Jerry, which is 6000? turns of 28ga. > > > Using Larry's board and the DataQ, its producing a very nice signal. > I placed the whole thing in a 5 gallon bucket and covered the top of > the bucket with towels to isolate most of the parts, from air > currents. The ball point pen and the top 20" of the dowel are exposed. > > The signal looks strong, I turned the gain on AmaSeis down to 2, which > is about what I use on other sensors. > > Not a high tech sensor, but I am going to record some earthquakes and > see how they look.........if we get some earthquakes. > > Thanks everyone. > Ted -- I think a picture would definately help...

Ian

tchannel1@............ wrote:
Hi All,  I am now testing the PMG  Paper mate Lubriglide, SENSOR,   This took well over a hour and I did not have to go to the hardware store once.
 
My camera battery is down, but if someone would like some picts just email me.  I know a pict is worth a thousand words, but I will try to describe it.
 
1.  I use a 1/8" x 36" wood dowel, taped a Paper-Mate pen refill to it, ball end up.
2.  I use a camera tripod, and attached a rare earth magnet to the handle of the tripod, (the tilting handle which is steel). Using the crank on the tripod I can raise and lower the dowel.
3.  I found a small steel nut which I could thread onto the dowel, a washer on top of the nut, then a larger hex nut, about 1/4" 20 thread. on top of the washer.
 This created a base for two bar magnets,(the washer) and a shoulder for the ends of the  magnets.(the larger nut)  So left to right= magnet+nut+magnet   The small nut and washer supports the magnets so they don't fall down the dowel.
By threading the small nut and washer up and down the dowel you change the magnets height.
 
 4. I used two small bar magnets, 1/4" x 1/2" x 1" 
 
 I turned the crank on the tripod lowering the two magnets to within 1/16" above the coil. ( Coil laying flat, dowel passing thru center hole, of the coil spool, two bar magnets, left and right= N and S, just above the plastic coil spool.)   This also lowered the end of the dowel deeper into the oil.
 
5.  I laid the  doe nut shaped coil, laying flat, on top of a small plastic cup, filled will oil as a damper.
 
6.  The dowel passes thru the coil spool and extends into the oil.  I did not use a paddle on the dowel, it seems to damp well by adding more oil.
 
The coil I got from friend Jerry, which is 6000? turns of 28ga.
 
 
Using Larry's board and the DataQ, its producing a very nice signal.   I placed the whole thing in a 5 gallon bucket and covered the top of the bucket with towels to isolate most of the parts, from air currents.   The ball point pen and the top 20" of the dowel are exposed.
 
The signal looks strong, I turned the gain on AmaSeis down to 2, which is about what I use on other sensors.
 
Not a high tech sensor, but I am going to record some earthquakes and see how they look.........if we get some earthquakes.
 
Thanks everyone.
Ted

--
Subject: horologist input From: Randall Peters PETERS_RD@.......... Date: Sun, 11 Nov 2007 09:40:27 -0500 Bob, Thanks for your comments. To the rest of you readers--clockmakers have indeed learned a great deal about the issues we've been discussing. When I wrote an article about a flex-pendulum, online at http://arxiv.org/ftp/physics/papers/0306/0306088.pdf Bob or one of his associates (I've got so much going on right now I haven't taken time to dig out the letter, and 'senior moments' seem to be unavoidable) pointed out to me that similar studies have been done in the past as part of the effort to improve horology. As noted in his letter, it would be difficult to come up with an idea that is truly original. This points to the following fact--we collectively (amateur seismology and horology) have something truly significant to offer the world of seismology. Anybody who has seriously tinkered with mechanical oscillators knows that friction is the 'name of the game' when it comes to the design of a seismometer. Because nobody properly understands from theory the friction responsible for instrument limitations, experiment is the key to success. Faraday and others were not above 'dirtying their hands' to see what worked. In his case, what proved successful had nothing to do with 'eyewash' (beautifully crafted but worthless instruments)--rather the focus was on the 'truth' of the physics. For those of you who know little about Faraday, I recommend that you read the following http://www.rigb.org/heritage/faradaypage.jsp If you look at the many discoveries that he made, you'll see that his methods of doing science were not what we see for the most part today. In my career I've seen a tragic progression into what can best be described as "data-taking technicians" who have little practical knowledge of the instruments they use. Scientists who try, or even think about building their own instruments are an increasingly rare scientific commodity. This is tragic because the approach departs radically from the methods on which physics was founded. I have attempted to document these claims in the chapter, "Building on old foundations with new technologies", part of a book scheduled for release in January, by Nova Science Publishers, titled "Science education in the 21st century" .ISBN: 1-60021-951-9 On separate matters: Ian, your paper-mate-lubriglide pendulum is great! I am curious, however, as to why you want to use the messy oil (or any other) damper. The primary reason for eliminating transient response is for purpose of conventional data interpretation. The inability to distinguish between Love and Rayleigh waves (as an example) because of the spherical motion means this is not very important for your system. Moreover, the period (which I missed if you mentioned it) is I suspect long enough that local noise disturbances are not as important as otherwise might be the case and for which conventional damping helps a lot. To just see earthquakes (for an alarms, as an example) you are likely to be better off eliminating the damping--partly because dithering by local noises is actually an advantage. I know that some folks believe that such an approach is tantamount to 'heresy'. I have already proven to my own satisfaction that what I'm saying is not ridiculous. Moreover, I personally believe that strong resistance to the thought suggests some of the blindness that results when we get trapped in the rut of conventional thinking. As I heard a theologian once say, a 'rut' is a 'coffin' with the ends kicked out. Meredith, You mention 'standard' crossed rods oscillating up to about 4 times longer than your present arrangement with magnets. If your 'standard' setup has no magnets, then I predict that a big part of this difference derives from eddy current damping due to the induced currents in the steel rods as the oscillate in the strong magnetic field of your gold-coated units. This eddy current component is not a 'show-stopper' like the mechnical internal friction parts. It is actually advantageous. Randall Subject: magnetic axis/pivot/crossed rod / ball point etc From: Angel sismos@.............. Date: Sun, 11 Nov 2007 15:15:01 +0000 Hi all, neat topics, I like the double ball point and magnetic axis/pivot/crossed rod ideas and have included a rough sketch of a possible arrangement. http://volcanbaru.com/OSOP/pics/crude_1_third_3_C_seismo.jpg Using the spring would be very traditional and one of many feed back mechanism could be used. I have always been fascinated by floating magnet things and offer this page. http://www.instructables.com/id/Electromagnetic-Floater/ Maybe the spring could be done away with and then use the floating magnet for positioning and some finer motion sensor could be used in the feedback, maybe like Allan's http://mysite.verizon.net/ressczez/sitebuildercontent/sitebuilderfiles/mkxi.pdf Use three of these arranged orthogonally at 120 degrees to derive all three components, like most modern broadband do. Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: magnetic axis/pivot/crossed rod / ball point etc From: "meredith lamb" paleoartifact@......... Date: Sun, 11 Nov 2007 12:11:30 -0700 Hi Angel and all, Of course the web is loaded with pendulums articles. One I kind of like for its simplistic graphics is at: http://www.phy.mtu.edu/~suits/PH3110/pendulums.html The servo type levitation web reference below would prove to be "jerky". The same web site reference above; even references on a "magnetic levitation pendulum"; which uses pyrolytic graphite and levitates above a arrangement of magnets in a "trap". It "acts" like a pendulum...but it is more reasonably termed as a tiltmeter; as the mass is so light, that there isn't much of any enertia component via the mass weight. A fair representation of a diamagnetic levitation patent (instrument) can be seen on Google; under their patent search feature. Its patent # 3831287 "Apparatus with adjustable period for measuring small diviations from a true horizontal plane". Anymore, with long neo magnets and with being polarized correctly (through the thickness, not the length), its relatively easy to obtain both the magnets and pyrolytic graphite.....and, one doesn't need all that iron (except for a flat and ~1/4" thick base plate); as they show on the dated patent. That stuff is a old interest of mine...but....I think I kind of get bored after awhile and go on to something else...a character flaw I guess....ha. A earlier model (1968) claims that instrument could clearly see earth tides....but I think the "rough" variation of the 1974 year model could well do the same. Meredith Lamb On Nov 11, 2007 8:15 AM, Angel wrote: > Hi all, > > neat topics, I like the double ball point and magnetic axis/pivot/crossed > rod ideas and have included a rough sketch of a possible arrangement. > > http://volcanbaru.com/OSOP/pics/crude_1_third_3_C_seismo.jpg > > > Using the spring would be very traditional and one of many feed back > mechanism could be used. > > I have always been fascinated by floating magnet things and offer this > page. > > http://www.instructables.com/id/Electromagnetic-Floater/ > > Maybe the spring could be done away with and then use the floating magnet > for positioning and some finer motion sensor could be used in the feedback, > maybe like Allan's > > > http://mysite.verizon.net/ressczez/sitebuildercontent/sitebuilderfiles/mkxi.pdf > > > Use three of these arranged orthogonally at 120 degrees to derive all > three components, like most modern broadband do. > > Angel > > > > >
Hi Angel and all,
 
Of course the web is loaded with pendulums articles.  One I kind of like for its simplistic graphics
is at:
 
The servo type levitation web reference below would prove to be "jerky".  The same web site
reference above; even references on a "magnetic levitation pendulum"; which uses
pyrolytic graphite and levitates above a arrangement of magnets in a "trap".   It "acts" like a
pendulum...but it is more reasonably termed as a tiltmeter; as the mass is so light, that
there isn't much of any enertia component via the mass weight.  A fair representation of a
diamagnetic levitation patent (instrument) can be seen on Google; under their patent search feature.  Its
patent # 3831287 "Apparatus with adjustable period for measuring small diviations from a
true horizontal plane".  Anymore, with long neo magnets and with being polarized correctly
(through the thickness, not the length), its relatively easy to obtain both the magnets and
pyrolytic graphite.....and, one doesn't need all that iron (except for a flat and ~1/4" thick base
plate); as they show on the dated patent.  That stuff is a old interest of mine...but....I think
I kind of get bored after awhile and go on to something else...a character flaw I guess....ha.
A earlier model (1968) claims that instrument could clearly see earth tides....but I think
the "rough" variation of the 1974 year model could well do the same.
 
Meredith Lamb 

On Nov 11, 2007 8:15 AM, Angel <sismos@..............> wrote:
Hi all,

neat topics, I like the double ball point and magnetic axis/pivot/crossed rod ideas and have included a rough sketch of a possible arrangement.

http://volcanbaru.com/OSOP/pics/crude_1_third_3_C_seismo.jpg


Using the spring would be very traditional and one of many feed back mechanism could be used.

I have always been fascinated by floating magnet things and offer this page.

http://www.instructables.com/id/Electromagnetic-Floater/

Maybe the spring could be done away with and then use the floating magnet for positioning and some finer motion sensor could be used in the feedback, maybe like Allan's

http://mysite.verizon.net/ressczez/sitebuildercontent/sitebuilderfiles/mkxi.pdf


Use three of these arranged orthogonally at 120 degrees to derive all three components, like most modern broadband do.

Angel





Subject: Re: horologist input From: "Geoff" gmvoeth@........... Date: Sun, 11 Nov 2007 16:06:22 -0700 Guten Tag Herrin Und Etwas; That Is All Fine And Well But According to them who knows at the Universities and in Corporate America The days for Discovery By the Single individual were over quite some time ago. Practically everything easy to Discover has already been discovered and today it takes the resources and monies of Nations to Discover anything New that is worthwhile. That is why people like DEC and Probably HP and others make their workers Sign a legal agreement that while they work and ten years after they dont they must get the approval from who they used to work for before taking any personal credt for patents and stuff. THIS is why I do not take any Amature group very serious. Unless they have been invaded somehow by professionals instead of amateures ( people who get no money for what they do ). Regards geoff ----- Original Message ----- From: "Randall Peters" To: Sent: Sunday, November 11, 2007 7:40 AM Subject: horologist input > Bob, > Thanks for your comments. To the rest of you readers--clockmakers have indeed learned a great deal > about the issues we've been discussing. When I wrote an article about a flex-pendulum, online at > http://arxiv.org/ftp/physics/papers/0306/0306088.pdf > Bob or one of his associates (I've got so much going on right now I haven't taken time to dig out the letter, and 'senior > moments' seem to be unavoidable) pointed out to me that similar studies have been done in the past as part of the effort to > improve horology. As noted in his letter, it would be difficult to come up with an idea that is > truly original. > This points to the following fact--we collectively (amateur seismology and horology) have something > truly significant to offer the world of seismology. Anybody who has seriously tinkered with mechanical oscillators knows that > friction is the 'name of the game' when it comes to the design of a seismometer. Because nobody properly understands from theory > the friction responsible for instrument limitations, experiment is the key to success. Faraday and others were not above > 'dirtying their hands' to see what worked. In his case, what proved > successful had nothing to do with 'eyewash' (beautifully crafted but worthless instruments)--rather the focus was > on the 'truth' of the physics. For those of you who know little about Faraday, I recommend that you read the > following > http://www.rigb.org/heritage/faradaypage.jsp > If you look at the many discoveries that he made, you'll see that his methods of doing science were not what we > see for the most part today. In my career I've seen a tragic progression into what can best be described as > "data-taking technicians" who have little practical knowledge of the instruments they use. Scientists who try, > or even think about building their own instruments are an increasingly rare scientific commodity. This is tragic because the > approach departs radically from the methods on which physics was founded. I have attempted to document these claims in the > chapter, "Building on old foundations with new technologies", part of a book scheduled for release in January, by Nova Science > Publishers, titled "Science education in the > 21st century" .ISBN: 1-60021-951-9 > On separate matters: > Ian, > your paper-mate-lubriglide pendulum is great! I am curious, however, as to why you want to use > the messy oil (or any other) damper. The primary reason for eliminating transient response is for purpose > of conventional data interpretation. The inability to distinguish between Love and Rayleigh waves (as an example) because of the > spherical motion means this is not very important for your system. Moreover, the period (which I missed if you mentioned it) is I > suspect long enough that local noise disturbances are not as important as otherwise might be the case and for which conventional > damping helps a lot. To just see earthquakes (for an alarms, as an example) you are likely to be better off eliminating the > damping--partly because dithering by local noises is actually an advantage. I know that some folks believe that such an approach > is tantamount to 'heresy'. I have already > proven to my own satisfaction that what I'm saying is not ridiculous. Moreover, I personally believe that strong resistance to > the thought suggests some of the blindness that results when we get trapped in the rut of conventional > thinking. As I heard a theologian once say, a 'rut' is a 'coffin' with the ends kicked out. > Meredith, > You mention 'standard' crossed rods oscillating up to about 4 times longer than your present arrangement > with magnets. If your 'standard' setup has no magnets, then I predict that a big part of this difference derives > from eddy current damping due to the induced currents in the steel rods as the oscillate in the strong magnetic > field of your gold-coated units. This eddy current component is not a 'show-stopper' like the mechnical > internal friction parts. It is actually advantageous. > Randall > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: pendulum that generated 'rattle in seattle' From: "Geoff" gmvoeth@........... Date: Sun, 11 Nov 2007 16:47:56 -0700 Wunderbar, Thanks for the enlightenment; I still would like to know why voltages get higher near pointed objects sort of like a point is acting like a resistor so possibly you could get a good current moving that at the ends of a solid tapered piece of copper or silver or room temp superconductor might possibly generate decent voltages without all those loops of fine wire. Just a thought relating to antennas I used to play with, you can increase the impedances by using a gamma match ( smaller diameter conductor ) or by tapering their ends at the feed point on the driven element ?? Do you know someone who makes and sells decent magnet coil sensors possibly according to my own wishes. I lack the resources to anything decent myself. I like that vertical seismometer that looks similar to a horizontal garden gate type but none seem to have a sensor arrangement which i like to see ?? I have looked into custom springs but like the Century people want $100 + USD just to make a single spring ( They call it setup costs ) ?? I guess if people like the spring one get somekind of gratuity in return from the company ?? Thanks for your replies. I always like hearing from science peoples about science stuff. Here in SandRock Arizona we seem to be in the Stix. Regards; geoff ----- Original Message ----- From: "Randall Peters" To: Sent: Saturday, November 10, 2007 8:21 AM Subject: pendulum that generated 'rattle in seattle' > Geoff, > The pendulum responsible for the now-famous picture you and Meredith mention (and give the American Physical Society-hosted > sebsite) is not like the dangling pendulum we've been discussing. > As you noted, it is a 'toy'-version of the one that I studied (responsible for the aforementioned article on chaos) and which > has for years been used to generate beautiful art-pieces. > A picture of that pendulum which I built (while still at Texas Tech University) and which is here in the Mercer physics department > is to be found at > http://physics.mercer.edu/Science_Art/bowling_ball.htm > Also on this website are some of the myriad traces that have been produced with the pendulum. Art-folks love these because > of their 'life-like' properties--no two exactly the same (quite unlike computer generated patterns). > The bowling ball is supported by a pipe on one end, the other end of which is connected to a universal joint (off a toyota > pickup if I remember correctly). Because of this U-joint, the x-y axes > are coupled, giving rise to a very large number of different patterns during free decay. The moments of inertia in the > two axes are adjustable to provide additional control that assists the near infinity of possible results. In the absence of > friction, this instrument would display what's called Hamiltonian chaos. The sensitive dependence on initial > conditions (essence of the butterfly effect) means that long term prediction (just like the weather) is > unpredictable. There are two capacitive sensors that map the motion of the bowling ball, one in each of the perpendicular axes. > The output from the amplified signals is fed to an x-y (analog recorder) that with a ball-point > pen generates the images on ordinary paper. > I have done a lot of chaos research in the last 15 years. The chaotic pendulum that I designed and which is > online here at Mercer (when my colleague Matt Marone gets it back operational after our move to the new > building) is at > http://physics.mercer.edu/PENDULUM/ > This pendulum can be controlled from anywhere in the world over the internet when operational. The parameter > that the user can adjust is the frequency of the drive. The pendulum's motion is monitored by one of my SDC > sensors functioning as a velocity detector. An aluminum disk rotates with the pendulum between rare-earth > magnets positioned on either side, which are on the end of a bending cantilever. The output (velocity) is integrated > with a 'leaky' integrator to give the position. > Largely because of my pendulum chaos studies I was asked and wrote an article on " math methods used by physicists to study > chaos" for the 10th Ed. of the McGraw Hill Encyclopedia of Science and Technology. I'm sure that some readers will note the > prominence of other authors in the chaos section of the encylopedia (such as the creator of the butterfly effect, Ed Lorenz) and > then will say, "but who's this guy, Peters?". > You ask, Geoff, 'why use multiple turn coils for the Faraday-law sensor. The answer is resident > within the statement of his law (generated, in the minds of most, by the greatest experimentalist who ever > lived). Faraday's law states that the voltage generated within the wire (historically called the electromotive force (emf) even > though voltage is not a force) is proportional to the number of turns of the coil times the time rate of change of the magnetic > flux passing through the coil. Thus no matter how your amplifier is built (solid state or vacuum tubes) the signal will be > greater the larger number of turns you can wind within the constraints of space limitations borne of wire size and increased > resistance that > results when the wire gets too small trying to put more turns into a given place. > Randall > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: horologist input From: "meredith lamb" paleoartifact@......... Date: Sun, 11 Nov 2007 19:19:47 -0700 On Nov 11, 2007 7:40 AM, Randall Peters wrote: Hi Randall and all, Your eddy current damping statement below is interesting and likely applies. Anyway; I proceeded with some more experimentation today and put up 3 more pictures on the same web page: http://home.earthlink.net/~meredithlamb/magneticaxispivot/ I put the magnets atop the steel block "mast". This makes it alot easier to manipulate the magnets/mechanics. I added some soft iron spring material I salvaged from (I think) a Kodac disposable camera, and that helped alot with regard to the free oscillation time which was about 70 minutes plus. It spend alot of time (~20 minutes) oscillating when it was less than a 1/32" total span; which essentially means it would be quite effective as is for a amateur horizontal enertia pendulum. Meredith Lamb > Meredith, > You mention 'standard' crossed rods oscillating up to about 4 times longer > than your present arrangement > with magnets. If your 'standard' setup has no magnets, then I predict > that a big part of this difference derives > from eddy current damping due to the induced currents in the steel rods as > the oscillate in the strong magnetic > field of your gold-coated units. This eddy current component is not a > 'show-stopper' like the mechnical > internal friction parts. It is actually advantageous. > Randall > > >

On Nov 11, 2007 7:40 AM, Randall Peters <PETERS_RD@..........> wrote:
 
Hi Randall and all,
 
Your eddy current damping statement below is interesting and likely applies.  Anyway;
I proceeded with some more experimentation today and put up 3 more pictures on the same web page:
 
 
I put the magnets atop the steel block "mast".  This makes it alot easier to manipulate the
magnets/mechanics.
 
I added some soft iron spring material I salvaged from (I think) a Kodac disposable camera, and
that helped alot with regard to the free oscillation time which was about 70 minutes plus.  It
spend alot of time (~20 minutes) oscillating when it was less than a 1/32" total span; which
essentially means it would be quite effective as is for a amateur horizontal enertia pendulum. 
 
Meredith Lamb
 
   Meredith,
You mention 'standard' crossed rods oscillating up to about 4 times longer than your present arrangement
with magnets.  If your 'standard' setup has no magnets, then I predict that a big part of this difference derives
from eddy current damping due to the induced currents in the steel rods as the oscillate in the strong magnetic
field of your gold-coated units.  This eddy current component is not a 'show-stopper' like the mechnical
internal friction parts.  It is actually advantageous.
 Randall

Subject: Re: horologist input From: ChrisAtUpw@....... Date: Sun, 11 Nov 2007 21:26:59 EST In a message dated 12/11/2007, paleoartifact@......... writes: I added some soft iron spring material I salvaged from (I think) a Kodac disposable camera, and that helped alot with regard to the free oscillation time which was about 70 minutes plus. Hi Meredith, You just need a hard surface. Could you use a thin steel feeler gauge? Regards, Chris
In a message dated 12/11/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I added some soft iron spring material I salvaged from (I think) a Ko= dac=20 disposable camera, and
that helped alot with regard to the free oscillation time which was a= bout=20 70 minutes plus. 
Hi Meredith,
 
    You just need a hard surface. Could you use a t= hin=20 steel feeler gauge?
 
    Regards,
 
    Chris
Subject: Re: pendulum that generated 'rattle in seattle' From: tchannel1@............ Date: Sun, 11 Nov 2007 20:05:22 -0700 Geoff, Please where are you located? Ted ----- Original Message ----- From: "Geoff" To: Sent: Sunday, November 11, 2007 4:47 PM Subject: Re: pendulum that generated 'rattle in seattle' > Wunderbar, Thanks for the enlightenment; > > I still would like to know why voltages > get higher near pointed objects > sort of like a point is acting like a > resistor so possibly you could > get a good current moving that at the ends > of a solid tapered piece of copper > or silver or room temp superconductor > might possibly generate decent voltages > without all those loops of fine wire. > Just a thought relating to antennas > I used to play with, you can increase the > impedances by using a gamma match ( smaller > diameter conductor ) or by tapering their ends > at the feed point on the driven element ?? > > Do you know someone who makes and sells > decent magnet coil sensors possibly according > to my own wishes. I lack the resources to > anything decent myself. > > I like that vertical seismometer that looks > similar to a horizontal garden gate type > but none seem to have a sensor arrangement > which i like to see ?? > > I have looked into custom springs but like > the Century people want $100 + USD > just to make a single spring ( They call it > setup costs ) ?? > I guess if people like the spring one get > somekind of gratuity in return from the company ?? > > Thanks for your replies. > I always like hearing from science peoples > about science stuff. > Here in SandRock Arizona we seem to be in the Stix. > > Regards; > geoff > > > > > ----- Original Message ----- > From: "Randall Peters" > To: > Sent: Saturday, November 10, 2007 8:21 AM > Subject: pendulum that generated 'rattle in seattle' > > >> Geoff, >> The pendulum responsible for the now-famous picture you and Meredith >> mention (and give the American Physical Society-hosted sebsite) is not >> like the dangling pendulum we've been discussing. >> As you noted, it is a 'toy'-version of the one that I studied >> (responsible for the aforementioned article on chaos) and which has for >> years been used to generate beautiful art-pieces. >> A picture of that pendulum which I built (while still at Texas Tech >> University) and which is here in the Mercer physics department is to be >> found at >> http://physics.mercer.edu/Science_Art/bowling_ball.htm >> Also on this website are some of the myriad traces that have been >> produced with the pendulum. Art-folks love these because of their >> 'life-like' properties--no two exactly the same (quite unlike computer >> generated patterns). >> The bowling ball is supported by a pipe on one end, the other end of >> which is connected to a universal joint (off a toyota pickup if I >> remember correctly). Because of this U-joint, the x-y axes >> are coupled, giving rise to a very large number of different patterns >> during free decay. The moments of inertia in the >> two axes are adjustable to provide additional control that assists the >> near infinity of possible results. In the absence of friction, this >> instrument would display what's called Hamiltonian chaos. The sensitive >> dependence on initial >> conditions (essence of the butterfly effect) means that long term >> prediction (just like the weather) is >> unpredictable. There are two capacitive sensors that map the motion of >> the bowling ball, one in each of the perpendicular axes. The output from >> the amplified signals is fed to an x-y (analog recorder) that with a >> ball-point >> pen generates the images on ordinary paper. >> I have done a lot of chaos research in the last 15 years. The chaotic >> pendulum that I designed and which is >> online here at Mercer (when my colleague Matt Marone gets it back >> operational after our move to the new >> building) is at >> http://physics.mercer.edu/PENDULUM/ >> This pendulum can be controlled from anywhere in the world over the >> internet when operational. The parameter >> that the user can adjust is the frequency of the drive. The pendulum's >> motion is monitored by one of my SDC >> sensors functioning as a velocity detector. An aluminum disk rotates >> with the pendulum between rare-earth >> magnets positioned on either side, which are on the end of a bending >> cantilever. The output (velocity) is integrated >> with a 'leaky' integrator to give the position. >> Largely because of my pendulum chaos studies I was asked and wrote an >> article on " math methods used by physicists to study chaos" for the 10th >> Ed. of the McGraw Hill Encyclopedia of Science and Technology. I'm sure >> that some readers will note the prominence of other authors in the chaos >> section of the encylopedia (such as the creator of the butterfly effect, >> Ed Lorenz) and then will say, "but who's this guy, Peters?". >> You ask, Geoff, 'why use multiple turn coils for the Faraday-law >> sensor. The answer is resident >> within the statement of his law (generated, in the minds of most, by the >> greatest experimentalist who ever >> lived). Faraday's law states that the voltage generated within the wire >> (historically called the electromotive force (emf) even though voltage is >> not a force) is proportional to the number of turns of the coil times the >> time rate of change of the magnetic flux passing through the coil. Thus >> no matter how your amplifier is built (solid state or vacuum tubes) the >> signal will be greater the larger number of turns you can wind within the >> constraints of space limitations borne of wire size and increased >> resistance that >> results when the wire gets too small trying to put more turns into a >> given place. >> Randall >> >> >> >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Magnets From: John Lahr johnjan@........ Date: Sun, 11 Nov 2007 19:56:40 -0800 How about using the hemitite magnets that are made to toss in the air and rattle? They are quite hard and polished, though clearly not as strong and NdFe. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Magnets, corrected spelling! From: John Lahr johnjan@........ Date: Sun, 11 Nov 2007 19:57:24 -0800 How about using the hematite magnets that are made to toss in the air and rattle? They are quite hard and polished, though clearly not as strong and NdFe. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Magnets, corrected spelling! From: ChrisAtUpw@....... Date: Sun, 11 Nov 2007 23:46:05 EST In a message dated 12/11/2007, johnjan@........ writes: How about using the hematite magnets that are made to toss in the air and rattle? They are quite hard and polished, though clearly not as strong and NdFeB. Hi John, They have a relatively weak maximum field and a ferocious temperature coefficient. Moreover, it is simply a matter of better design to incorporate magnets into the magnetic circuit in such a way that their physical limitations do not matter. You might, for instance, roll the bearing on hardened martensitic SS rods connected by mild steel blocks to flat NdFeB magnets? Regards, Chris Chapman
In a message dated 12/11/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>How=20 about using the hematite magnets that are made to toss in the air and=20 rattle?  They are quite hard and polished, though clearly not as stro= ng=20 and NdFeB.
Hi John,
 
    They have a relatively weak maximum fi= eld=20 and a ferocious temperature coefficient. 
 
    Moreover, it is simply a matter of bet= ter=20 design to incorporate magnets into the magnetic circuit in such a way=20 that their physical limitations do not matter. You might, for=20 instance, roll the bearing on hardened martensitic SS rods connected by= =20 mild steel blocks to flat NdFeB magnets?
 
    Regards,
 
    Chris Chapman
 
Subject: Re: horologist input From: "meredith lamb" paleoartifact@......... Date: Sun, 11 Nov 2007 22:43:44 -0700 Hi Chris, Excellent idea! Will have to check on my "stock" tomorrow; which has been chopped up over the years for various projects. Anyway....that approach is indeed likely very suitable and available in alot of places and over the internet. Thanks for your earlier positive email opinion of the use of magnets in a crossed rod or crossed cylinder axis/pivot, as that helped accelerate this experimentation. Using a layer of metal on magnets approach; reminds me of the good old diamagnetic levitation experiment times, which was also your very good idea for certain varieties of setups/models we saw. Meredith Lamb On Nov 11, 2007 7:26 PM, wrote: > In a message dated 12/11/2007, paleoartifact@......... writes: > > I added some soft iron spring material I salvaged from (I think) a Kodac > disposable camera, and > that helped alot with regard to the free oscillation time which was about > 70 minutes plus. > > Hi Meredith, > > You just need a hard surface. Could you use a thin steel feeler gauge? > > Regards, > > Chris >
Hi Chris,
 
Excellent idea!  Will have to check on my "stock" tomorrow; which has been chopped up over the years
for various projects.  Anyway....that approach is indeed likely very suitable and available in alot of places
and over the internet.  Thanks for your earlier positive email opinion of the use of magnets in a crossed rod
or crossed cylinder axis/pivot, as that helped accelerate this experimentation.  
 
Using a layer of metal on magnets approach; reminds me of the good old diamagnetic levitation experiment
times, which was also your very good idea for certain varieties of setups/models we saw. 
 
Meredith Lamb

On Nov 11, 2007 7:26 PM, <ChrisAtUpw@.......> wrote:
In a message dated 12/11/2007, paleoartifact@......... writes:
I added some soft iron spring material I salvaged from (I think) a Kodac disposable camera, and
that helped alot with regard to the free oscillation time which was about 70 minutes plus. 
Hi Meredith,
 
    You just need a hard surface. Could you use a thin steel feeler gauge?
 
    Regards,
 
    Chris

Subject: Glass? From: tchannel1@............ Date: Mon, 12 Nov 2007 08:47:17 -0700 Hi Folks, Just wondering about materials for roller on roller or balls = on plates. I know the limitations of glass, but a question about its = smoothness, is the surface of glass as smooth or smoother than these = hardened and polished steels? My second question is one of friction: If you have one ball on one = plate you would have one point of friction. If you have one ball = resting between two rollers, ( in the V) you would have two points of = friction, but the load would be divided, because its resting on two = points, so is the end result of friction loss the same???? =20 Thanks, Ted
Hi Folks,   Just wondering = about=20 materials for roller on roller or balls on plates.   I know = the=20 limitations of glass, but a question about its smoothness, is the = surface of=20 glass as smooth or smoother than these hardened and polished=20 steels?
 
My second question is one of = friction:  =20 If you have one ball on one plate you would have one point of=20 friction.   If you have one ball resting between two = rollers, ( in the V) you would have two points of friction, but the load = would=20 be divided, because its resting on two points, so is the end result = of=20 friction loss the same???? 
 
Thanks, Ted
 
Subject: Re: Glass? From: ChrisAtUpw@....... Date: Mon, 12 Nov 2007 12:07:26 EST In a message dated 12/11/2007, tchannel1@............ writes: Hi Folks, Just wondering about materials for roller on roller or balls on plates. I know the limitations of glass, but a question about its smoothness, is the surface of glass as smooth or smoother than these hardened and polished steels? Hi Ted, Probably about the same. You get an optical finish with fine polish on metal. However glass is a rapidly solidified liquid. My second question is one of friction: If you have one ball on one plate you would have one point of friction. If you have one ball resting between two rollers, (in the V) you would have two points of friction, but the load would be divided, because its resting on two points, so is the end result of friction loss the same? It is the surface to surface properties which are important. The actual static friction is proportional to the load, so halving it and using two points will likely give a very similar result. However, if you put a fixed vertical load on a ball resting on two rods, the loads at the two points are increased to give the same resolved vertical force. When we talk about friction in pendulum suspensions, it is not this static friction to which we are referring. It is the tiny rolling contact loss as the materials are compressed and relaxed. No materials are perfectly elastic. Glass is poor in this respect and tends to chip easily. Regards, Chris
In a message dated 12/11/2007, tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Folks,   Just wondering abou= t=20 materials for roller on roller or balls on plates.   I know the=20 limitations of glass, but a question about its smoothness, is the surface=20= of=20 glass as smooth or smoother than these hardened and polished=20 steels?
Hi Ted,
 
    Probably about the same. You get an optical fin= ish=20 with fine polish on metal. However glass is a rapidly solidified liquid. <= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
My second question is one of friction: If= you=20 have one ball on one plate you would have one point of friction.  If=20= you=20 have one ball resting between two rollers, (in the V) you would=20= have=20 two points of friction, but the load would be divided, because its resting= on=20 two points, so is the end result of friction loss the=20 same?
    It is the surface to surface properties which a= re=20 important. The actual static friction is proportional to the load, so=20 halving it and using two points will likely give a very similar result. Howe= ver,=20 if you put a fixed vertical load on a ball resting on two rods, the loa= ds=20 at the two points are increased to give the same resolved vertical=20 force.  
 
    When we talk about friction in pendulum=20 suspensions, it is not this static friction to which we are referring. It is= the=20 tiny rolling contact loss as the materials are compressed and relaxed. No=20 materials are perfectly elastic. Glass is poor in this respect and tends to=20= chip=20 easily.
 
    Regards,
 
    Chris
Subject: Re: Glass? From: tchannel1@............ Date: Mon, 12 Nov 2007 11:35:41 -0700 Chris, You have enlighten me. "Not to put too fine a point on it" = (the subject that is) but would then, diamond on diamond be the best of = all? Not knowing how I might do this, but I have many carbide tipped saw = blades. I have never looked too closely at one tooth, but they have a = point and some flat surfaces. If I could get some of these teeth off, = or get replacement teeth from the people who resharpen my blades, would = these be good pivots surfaces? Say one tooth point resting on one tooth = flat side. (arranged in a set of two) pivots for a vertical pendulum? = Thanks, Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Monday, November 12, 2007 10:07 AM Subject: Re: Glass? In a message dated 12/11/2007, tchannel1@............ writes: Hi Folks, Just wondering about materials for roller on roller or = balls on plates. I know the limitations of glass, but a question about = its smoothness, is the surface of glass as smooth or smoother than these = hardened and polished steels? Hi Ted, Probably about the same. You get an optical finish with fine = polish on metal. However glass is a rapidly solidified liquid. My second question is one of friction: If you have one ball on one = plate you would have one point of friction. If you have one ball = resting between two rollers, (in the V) you would have two points of = friction, but the load would be divided, because its resting on two = points, so is the end result of friction loss the same? It is the surface to surface properties which are important. The = actual static friction is proportional to the load, so halving it and = using two points will likely give a very similar result. However, if you = put a fixed vertical load on a ball resting on two rods, the loads at = the two points are increased to give the same resolved vertical force. =20 When we talk about friction in pendulum suspensions, it is not = this static friction to which we are referring. It is the tiny rolling = contact loss as the materials are compressed and relaxed. No materials = are perfectly elastic. Glass is poor in this respect and tends to chip = easily. Regards, Chris
Chris,   You have enlighten me.   "Not to = put too=20 fine a point on it"  (the subject that is) but  would = then,=20 diamond on diamond be the best of all?
 
Not knowing how I might do this, but I have many carbide tipped saw = blades.  I have never looked too closely at one tooth, but they = have a=20 point and some flat surfaces.  If I could get some of these teeth = off, or=20 get replacement teeth from the people who resharpen my blades, would = these be=20 good pivots surfaces?  Say one tooth point resting on one tooth = flat=20 side.  (arranged in a set of two) pivots for a vertical=20 pendulum?   Thanks, Ted
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Monday, November 12, 2007 = 10:07=20 AM
Subject: Re: Glass?

In a message dated 12/11/2007, tchannel1@............ = writes:
Hi Folks,   Just = wondering about=20 materials for roller on roller or balls on plates.   I = know the=20 limitations of glass, but a question about its smoothness, is the = surface of=20 glass as smooth or smoother than these hardened and polished=20 steels?
Hi Ted,
 
    Probably about the same. You get an = optical=20 finish with fine polish on metal. However glass is a rapidly = solidified=20 liquid.
My second question is one of = friction: If you=20 have one ball on one plate you would have one point of = friction.  If=20 you have one ball resting between two rollers, (in the V) = you=20 would have two points of friction, but the load would be divided, = because=20 its resting on two points, so is the end result of friction = loss the=20 same?
    It is the surface to surface properties = which are=20 important. The actual static friction is proportional to the = load, so=20 halving it and using two points will likely give a very similar = result.=20 However, if you put a fixed vertical load on a ball resting on two = rods,=20 the loads at the two points are increased to give the same = resolved=20 vertical force.  
 
    When we talk about friction in pendulum=20 suspensions, it is not this static friction to which we are referring. = It is=20 the tiny rolling contact loss as the materials are compressed and = relaxed. No=20 materials are perfectly elastic. Glass is poor in this respect and = tends to=20 chip easily.
 
    Regards,
 
=
    Chris
Subject: glass+other issues From: Randall Peters PETERS_RD@.......... Date: Mon, 12 Nov 2007 14:21:16 -0500 Ted, Your question about tungsten carbide tips. I have used ones off of saw blades as you are contemplating. They can be easily removed by heating with a propane torch and then re-brazed on whatever your pendulum attachment position should be, if of steel. The research pendulum that I built several years ago performs well by using diamond on sapphire. The diamond points were taken out of old phonograph stylus units and the sapphire flats are probably not too difficult to come by. In my case they were surplused from old mass-balances (common to weigh chemicals in chemistry class before the advent of digital balances). The problem with the saw-blade tips is that they are designed to cut, not rock on a flat surface. The sharp points will dig into most surfaces. A pendulum that I have on the pier here at Mercer that works quite well uses ball-point pen extracts resting on sapphire. I can't tell a significant difference between its performance and the one that used diamond points. Angel, I like your thoughts about magnetic 'floaters'. The first time I built a system to do the same system as the system described in the webpage you referenced was when I was a student more than 40 years ago. The Jesse Beams Laboratory at the University of Virginia is named in honor of the professor who perfected high angular speed experiments by this means. He studied the diffusion of atoms in solids by an elegant (very non-conventional type of centrifuge)-- spinning ball bearings, by means of a rotating magnetic field in a vacuum, to a high enough angular velocity that the tensile strength of the metal would begin to be called into question. I understand that he was able (in vacuum) to actually spin them until they flew apart! Things that hang below magnets are fascinating for reason of their 'defiance' of Earnshaw's theorem. In the case of permanent magnets, there can be no stable equilibrium of the type demonstrated in this webpage. There is an example of a stable equilibrium that looks similar, that requires no feedback. Serendipity by a single individual (not the prowess of a well-funded corporation, Geoff) figured into its discovery by my brother Palmer Peters. It is called the 'suspension effect' of high Tc superconductors. http://query.nytimes.com/gst/fullpage.html?sec=health&res=940DEFD7143CF933A1575AC0A96E948260 The flux-pinning that results when you add silver to the cuprate superconductors gives them fascinating properties. Palmer worked with M.K. Wu sho supplied him with the samples and who was the first to make the first high Tc sample (Y-BaCuo). About your sketch, Angel: Would it be possible for you to have the points contacting the magnets in a 'pull away' manner as opposed to 'push-against' one? This would reduce the normal force and thus the friction. Randall Subject: Re: glass+other issues From: Angel sismos@.............. Date: Mon, 12 Nov 2007 19:54:15 +0000 Hello Randall, > Would it be possible for you to have the points contacting the > magnets in a 'pull away' manner as opposed to 'push-against' one? > This would reduce the normal force and thus the friction. What a good idea. That would be quite easy, Just rotating the drawing 180 degrees. I should have thunk of that myself. I may just build one of these just to see if the thing jitters. I would be adjusting the feedback system several hundred times per second. Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Rolling Suspensions From: ChrisAtUpw@....... Date: Mon, 12 Nov 2007 17:31:48 EST In a message dated 12/11/2007, tchannel1@............ writes: Chris, but would then, diamond on diamond be the best of all? Not knowing how I might do this, but I have many carbide tipped saw blades. I have never looked too closely at one tooth, but they have a point and some flat surfaces. If I could get some of these teeth off, or get replacement teeth from the people who resharpen my blades, would these be good pivots surfaces? Say one tooth point resting on one tooth flat side. (arranged in a set of two) pivots for a vertical pendulum? Thanks, Ted Hi Ted, You can get elliptical diamond tips for sound cartridges, but they won't take much load. But you could probably use them as miniature cylinders? Also sapphire tips, but they are very small. I think that you can in principle buy sapphire balls, cylinders and flats, but I don't have a source. They are all manufactured. What on earth do you want saw tooth blades for? Knife edge and true point suspensions don't work well or for long. Forget them. If you have a really sharp edge or a point and put a significant load on it, you will exceed the strength of the edge / tip material FOR CERTAIN. The edge may 1) roll over 2) compress 3) chip / shatter 4) dig into the counterface. This is GUARANTEED eventual FAILURE, probably sooner rather than later and it is really dumb. The so called 'knife edge bearings' used on chemical balances have the edge lapped to give a tiny half cylinder, with a max load of maybe 200 gm only. Any more and they shatter. Rolling spheres and rolling cylinders both work fine. Have a look at _www.smallparts.com_ (http://www.smallparts.com) ? You can use Martensitic SS ball bearings. They are cheap. You can also get Tungsten Carbide Balls. BIC pens also use 1 mm ones. You can buy Martensitic Stainless Steel rod in a wide range of sizes. It is cheap. You can buy Tungsten Carbide needle bearings. You can buy Tungsten Carbide drills and use the shanks, ordinary drill form or 1/8" // shank types. For flats, you can buy Martensitic Stainless Steel sheet. It is cheap. You can buy solid triangular Tungsten Carbide tool tips for lathe tools. You can buy Tungsten Carbide scraper blades, bar shaped or trianglar. You can buy Tungsten Carbide cutter blades for electric planes. You can buy diamond and corundum paste for lapping and polishing surfaces, which you can do with sheet copper. Has anyone else out there found any other sources? Regards, Chris Chapman
In a message dated 12/11/2007, tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Chris,   but would then, diamond on diamond be the best of=20= all?=20
 
Not knowing how I might do this, but I have many carbide tipped saw=20 blades. I have never looked too closely at one tooth, but they have a= =20 point and some flat surfaces. If I could get some of these teeth off,= or=20 get replacement teeth from the people who resharpen my blades, would these= be=20 good pivots surfaces? Say one tooth point resting on one tooth flat=20 side.  (arranged in a set of two) pivots for a vertical=20 pendulum?   Thanks, Ted
Hi Ted,
 
    You can get elliptical diamond tips for so= und=20 cartridges, but they won't take much load. But you could probably use them a= s=20 miniature cylinders? Also sapphire tips, but they are very small. I think th= at=20 you can in principle buy sapphire balls, cylinders and flats, but I don't ha= ve a=20 source. They are all manufactured.
 
    What on earth do you want saw tooth blades for?= =20 Knife edge and true point suspensions don't work well or for long. Forg= et=20 them.
    If you have a really sharp edge or a point and=20= put=20 a significant load on it, you will exceed the strength of the edge / tip=20 material FOR CERTAIN. The edge may 1) roll over 2) compress 3) chip / shatte= r 4)=20 dig into the counterface. This is GUARANTEED eventual FAILURE, probably soon= er=20 rather than later and it is really dumb.
    The so called 'knife edge bearings' used on=20 chemical balances have the edge lapped to give a tiny half cylinder, with a=20= max=20 load of maybe 200 gm only. Any more and they shatter.
 
    Rolling spheres and rolling cylinders both work= =20 fine.
 
    Have a look at www.smallparts.com ?
 
    You can use Martensitic SS ball bearings. They=20= are=20 cheap.
    You can also get Tungsten Carbide Balls. B= IC=20 pens also use 1 mm ones.
 
    You can buy Martensitic Stainless Steel rod in=20= a=20 wide range of sizes. It is cheap.
    You can buy Tungsten Carbide needle bearings.
    You can buy Tungsten Carbide drills and use the= =20 shanks, ordinary drill form or 1/8" // shank types.
 
    For flats, you can buy Martensitic Stainless St= eel=20 sheet. It is cheap.
    You can buy solid triangular Tungsten Carbide t= ool=20 tips for lathe tools.
    You can buy Tungsten Carbide scraper blades, ba= r=20 shaped or trianglar.
    You can buy Tungsten Carbide cutter blades for=20 electric planes.
 
    You can buy diamond and corundum paste for lapp= ing=20 and polishing surfaces, which you can do with sheet copper.
 
    Has anyone else out there found any other=20 sources?
 
    Regards,
 
    Chris=20 Chapman   
Subject: BB raceway and rod pivot for a vertical From: "meredith lamb" paleoartifact@......... Date: Mon, 12 Nov 2007 16:13:34 -0700 Hi all, Here is another idea, for a possible vertical pivot. It uses the outer concave shaped ball bearing assembly raceway salvaged from a larger ball bearing assembly for one part of the pivot. I got the complete ball bearing assembly (used/discard) from a local surplus store for ~ $1.50. Of course one needs a raceway with the raceway on the outer shell; as alot of raceways could have it inside the shell. The rod resting in the (concave) raceway is smaller in diameter that the diameter than raceway was built for...this reduces the contact surface to one point. It would be relatively self centering in one lateral direction of course. One end of the rod can hold the spring; and of course the other end would be for the mass. Its very possible to have two such assemblys for added stability; and interconnect the "boom" rod/s...otherwise the boom would spin around the pivot contact without having to add some kind of mechanical control. http://home.earthlink.net/~meredithlamb/ballbearingracewaypivot/ With two such assemblys; the pivot in effect becomes a "crossed rod/cyclinder" pivot. In the picture (no text added yet), the bolts are only to keep the round raceway from rolling in the example picture....the raceway could be easily affixed to a "L" bracket/s. If you connect the read ends of the rods, and then add the spring (or possible two springs?), then the mass end of the unit shouldn't be too hard to control. I've yet no idea of the hardness of the raceway assembly; but I'd think it would be adequate. A tough Stainless steel rod could be used for the boom rod other side of the pivot contact. I used a abrasive cut off saw, to cut through the (not shown in the picture), outer shell of the original ball bearing assembly. Cutting it was easy with such a machine. Meredith Lamb
Hi all,
 
Here is another idea, for a possible vertical pivot.  It uses the outer concave shaped
ball  bearing assembly raceway salvaged from a larger ball bearing assembly
for one part of the pivot.  I got the complete ball bearing assembly (used/discard)
from a local surplus store for ~ $1.50.  Of course one needs a raceway with the
raceway on the outer shell; as alot of raceways could have it inside the shell.
 
The rod resting in the (concave) raceway is smaller in diameter that the diameter than
raceway was built for...this reduces the contact surface to one point.  It would be relatively self
centering in one lateral direction of course.  One end of the rod can hold the spring; and of
course the other end would be for the mass.
 
Its very possible to have two such assemblys for added stability; and interconnect the
"boom" rod/s...otherwise the boom would spin around the pivot contact without having
to add some kind of mechanical control.
 
 
With two such assemblys; the pivot in effect becomes a "crossed rod/cyclinder" pivot.
In the picture (no text added yet), the bolts are only to keep the round raceway from
rolling in the example picture....the raceway could be easily affixed to a "L" bracket/s.
If you connect the read ends of the rods, and then add the spring (or possible two springs?),
then the mass end of the unit shouldn't be too hard to control.
 
I've yet no idea of the hardness of the raceway assembly; but I'd think it would be
adequate.  A tough Stainless steel rod could be used for the boom rod other side of
the pivot contact.
 
I used a abrasive cut off saw, to cut through the (not shown in the picture), outer
shell of the original ball bearing assembly.  Cutting it was easy with such a machine.
 
Meredith Lamb
 
 
 
 
 
Subject: Glueing metal to metal From: "meredith lamb" paleoartifact@......... Date: Tue, 13 Nov 2007 22:02:01 -0700 Hi all, Am in need of a opinion/knowledge of a relatively fast curing and very good glue to afix a potential variety of thin film/sheet metal to gold plated neodymium magnets. This would be for the magnetic crossed rod experimental pivot/axis project. Some materials like thin "springy" thickness gauge/s, or security tags (acouto-magnetic and or magnetostrictive) just do not mechanically bend....like other more flexible thin metals. I've not tried heating the metal over a metal rod to possibly shape (not the magnets of course). I read on the internet (limited craftsman opinion); that the brand "JB weld" might be good.... Security tags may or may not be worth the use, as their composition seems to vary from manufacturer; or is a hodge-podge of metals. Theres probably other material out there (?) Thanks, Meredith Lamb
Hi all,
 
Am in need of a opinion/knowledge of a relatively fast curing and very good glue to afix
a potential variety of thin film/sheet metal to gold plated neodymium magnets.  This would
be for the magnetic crossed rod experimental pivot/axis project.
 
Some materials like thin "springy" thickness gauge/s, or security tags (acouto-magnetic and
or magnetostrictive) just do not mechanically bend....like other more flexible thin metals.
I've not tried heating the metal over a metal rod to possibly shape (not the magnets of course).
 
I read on the internet (limited craftsman opinion); that the brand "JB weld" might be good....
 
Security tags may or may not be worth the use, as their composition seems to vary from
manufacturer; or is a hodge-podge of metals.
 
Theres probably other material out there (?) 
 
Thanks, Meredith Lamb
 
 
Subject: knife edge materials & horological update From: holmstro@.......... Date: Wed, 14 Nov 2007 01:15:19 -0800 (PST) The HSN website has some preliminary information on knife edges for horology located at http://www.hsn161.com/knife.php A rounded edge is the key to success as Chris points out. If done properly, knife edge supported pendulums for clocks can be a great success - Reifler clocks for example. More appropriate to this discussion > The Granta Materials Intelligence web site at http://www.grantadesign.com/resources/materials/casestudies/pivots.htm discusses material choices for knife edges from an engineering point of view. The Granta site suggests that elastic and plastic deformation are important varibles to control in a knife edge suspension. "Elastic deformation is minimised by choosing materials with high Young’s modulus; plastic deformation is limited by choosing materials with high hardness. Granta suggests making a graph with Young’ modulus on one axis and and hardness on the other and pick the materials with high values of both. "The very best are all ceramics: boron carbide, silicon carbide and tungsten carbide. If the selection box is relaxed so that the first metals appear, the selection picks up medium carbon steel, high carbon steel and low alloy steel. All are sensible choices: the ceramics when the ultimate precision is required, the steels when robust design able to deal with shock loading is needed." re horology: Indium is not a good material for flexures, it is very soft - I ment to say Niobium (thanks Chris). EDM shaped Niobium flexures qre used in gravity wave detection pendulums - there must still be some losses but I do not know how they compare to some of the rolling solutions disccused on this list. Seaching for niobium on the HSN web site horological literature data base at http://www.hsn161.com/BHM/bhm1-allusers/bhmfind2.php yields 4 papers on niobium flexures in a title search plus a couple more using a keyword search. Searching for flexures yields many more hits. Note the BHM data base currently has more than 12000 horological and horological science references. Randall re Flex Pendulum Bob Matthys contacted you re the flex pendulum. He used a conventional pendulum with a flexure conected mass above the center of rotation to correct for circular error - the work was published in the Horological Journal. Bob's papers have been collected in a book published by Oxford University Press. The papers cover Bob's experimental work with clock pendulums including flexures, teperature compensation, material stability, etc. Bob Holmström Editor Horological Science Newsletter __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: knife edge materials & horological update From: ChrisAtUpw@....... Date: Wed, 14 Nov 2007 08:11:40 EST In a message dated 14/11/2007, holmstro@.......... writes: The HSN website has some preliminary information on knife edges for horology located at http://www.hsn161.com/knife.php A rounded edge is the key to success as Chris points out. If done properly, knife edge supported pendulums for clocks can be a great success - Reifler clocks for example. Hi Bob, Making a triangular rod and then accurately rounding, lapping and polishng the edge involves precision engineering. However, milling a short flat section on the tip end of say a 60 deg rod and then milling a small 90 deg V slot in this face to support a small diameter circular rod is quite possible. You can clean the components and glue the rod in place with two part acrylic glue. One other consideration not mentioned is that the materials need to be very resistant to oxidation / corrosion if used in damp air. Martensitic Stainless Steel, Tungsten Carbide and Sapphire are obvious 'candidates'. Materials suitable for use in high vaccum are more limited. If you use metals, you are likely to get welding when the protective oxide coats wear off. Some hard ceramics like sapphire are likely to be successful. Regards, Chris Chapman
In a message dated 14/11/2007, holmstro@.......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>The HSN=20 website has some preliminary information on knife edges for horology locat= ed=20 at http://www.hsn161.com/knife.php  A rounded edge is the key to= =20 success as Chris points out.  If done properly, knife edge supported=20 pendulums for clocks can be a great success - Reifler clocks for=20 example.
Hi Bob,
 
    Making a triangular rod and then accurately= =20 rounding, lapping and polishng the edge involves precision engineering. Howe= ver,=20 milling a short flat section on the tip end of say a 60 deg rod and=20 then milling a small 90 deg V slot in this face to support a=20 small diameter circular rod is quite possible. You can clean the components=20= and=20 glue the rod in place with two part acrylic glue.
    One other consideration not mentioned is that t= he=20 materials need to be very resistant to oxidation / corrosion if used in damp= =20 air. Martensitic Stainless Steel, Tungsten Carbide and Sapphire are=20 obvious 'candidates'. Materials suitable for use in high vaccum are mor= e=20 limited. If you use metals, you are likely to get welding when=20 the protective oxide coats wear off. Some hard ceramics like sapph= ire=20 are likely to be successful.
 
    Regards,
    
    Chris Chapman
 
Subject: Re: Glueing metal to metal From: ChrisAtUpw@....... Date: Wed, 14 Nov 2007 08:25:58 EST In a message dated 14/11/2007, paleoartifact@......... writes: Am in need of a opinion/knowledge of a relatively fast curing and very good glue to afix a potential variety of thin film/sheet metal to gold plated neodymium magnets. This would be for the magnetic crossed rod experimental pivot/axis project. Hi Meredith. Try DevWeld or similar. It comes in twin tubes and you mix equal quantities. The 'Use time' after mixing is about five minutes. It should be fully hard in an hour. Look at the Devcon website? _www.smallparts.com_ (http://www.smallparts.com) stock acrylic glue. You could also look for Holdtite 3295. Most of the US glue manufacturers including Permabond and Loctite produce one variety or another of two component Acrylic Glue. Look for two compoment Acrylic or Methacrylate glues. About the only other possibility is two component polyurethane, like one of the Bisonite range. Regards, Chris
In a message dated 14/11/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Am in need of a opinion/knowledge of a relatively fast=20 curing and very good glue to afix
a potential variety of thin film/sheet metal to gold plated neodymium= =20 magnets.  This would
be for the magnetic crossed rod experimental pivot/axis=20 project.
Hi Meredith.
 
    Try DevWeld or similar. It comes in twin tubes=20= and=20 you mix equal quantities. The 'Use time' after mixing is about five minutes.= It=20 should be fully hard in an hour. Look at the Devcon website? www.smallparts.com stock acrylic=20 glue.
    You could also look for Holdtite 3295. Most of=20= the=20 US glue manufacturers including Permabond and Loctite produce one variety or= =20 another of two component Acrylic Glue.
 
    Look for two compoment Acrylic or Methacrylate=20 glues.
    About the only other possibility is two compone= nt=20 polyurethane, like one of the Bisonite range.
 
    Regards,
 
    Chris
Subject: Knife Edge Discussion From: "Jerry Payton" gpayton880@....... Date: Wed, 14 Nov 2007 09:58:50 -0600 I am enjoying the discussions regarding the usage of a knife edge pivot point. If I understand correctly two points that were made were (1) that it is the hardness of the material and (2) a more rounded edge rather than sharp edge that is important. This leads me to a question. What would be the difference between using a hard "rounded" edge and using a hard ball bearing? (Size of curved surface is obvious.) Is it the groove that the edge fits into? Ted, told me about a method that he has used: two parallel roller bars and a ball fitting between them. Orientation of the bars would dictate whether horizontal of vertical movement of the arm. Regards to all, Jerry
I am enjoying the discussions regarding the usage of a knife edge = pivot=20 point.  If I understand correctly two points that were made were = (1) that=20 it is the hardness of the material and (2) a more rounded edge rather = than sharp=20 edge that is important. 
 
This leads me to a question.  What would be the difference = between=20 using a hard "rounded" edge and using a hard ball bearing?  (Size = of curved=20 surface is obvious.)  Is it the groove that the edge fits = into?  Ted,=20 told me about a method that he has used: two parallel roller bars and a=20 ball fitting between them.  Orientation of the bars would = dictate=20 whether horizontal of vertical movement of the arm.
 
Regards to all,
Jerry
Subject: Re: Knife Edge Discussion From: ChrisAtUpw@....... Date: Wed, 14 Nov 2007 11:42:37 EST In a message dated 14/11/2007, gpayton880@....... writes: I am enjoying the discussions regarding the usage of a knife edge pivot point. If I understand correctly two points that were made were (1) that it is the hardness of the material and (2) a more rounded edge rather than sharp edge that is important. Hi Jerry, If you use a really sharp knife edge you overload either the edge material or the counterface and get automatic failure. The edge may 1) roll over 2) distort / compress 3) chip or shatter depending on the blade angle, the material and the forces involved. If you round the edge to get a cylider rolling on a flat, you can choose the radius of curvature so that the metal is not at or close to it's limiting stress. If you put a cylinder in a sharp V slot and try to rotate it, it won't work well. If you put it in a semi circular trough of larger radius, it tends to maintain it's position while rolling freely. This leads me to a question. What would be the difference between using a hard "rounded" edge and using a hard ball bearing? (Size of curved surface is obvious.) Is it the groove that the edge fits into? Ted, told me about a method that he has used: two parallel roller bars and a ball fitting between them. Orientation of the bars would dictate whether horizontal of vertical movement of the arm. A ball bearing has a circular contact point with a flat, semi elliptical with a single curved surface. A cylinder on a flat has a line contact with rounded ends. This greater area and single curvature allows it to take much higher loads than a ball of the same radius, material and heat treatment. You can use ball bearings in a bicycle wheel. You have to use roller bearings in a lorry wheel. Regards, Chris Chapman
In a message dated 14/11/2007, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I am enjoying the discussions regarding the usage of a knife edge piv= ot=20 point.  If I understand correctly two points that were made were (1)=20= that=20 it is the hardness of the material and (2) a more rounded edge rather than= =20 sharp edge that is important. 
Hi Jerry,
 
    If you use a really sharp knife edge you overlo= ad=20 either the edge material or the counterface and get automatic failure.=20= The=20 edge may 1) roll over 2) distort / compress 3) chip or shatter depending on=20= the=20 blade angle, the material and the forces involved.
    
    If you round the edge to get a cylider rolling=20= on a=20 flat, you can choose the radius of curvature so that the metal is not at or=20 close to it's limiting stress. If you put a cylinder in a sharp V slot=20= and=20 try to rotate it, it won't work well. If you put it in a semi circular troug= h of=20 larger radius, it tends to maintain it's position while rolling freely.
This leads me to a question.  What would be the difference b= etween=20 using a hard "rounded" edge and using a hard ball bearing?  (Size of=20 curved surface is obvious.)  Is it the groove that the edge fits=20 into?  Ted, told me about a method that he has used: two parallel rol= ler=20 bars and a ball fitting between them.  Orientation of the bars w= ould=20 dictate whether horizontal of vertical movement of the=20 arm.
    A ball bearing has a circular contact poin= t=20 with a flat, semi elliptical with a single curved surface. A cylinder on a=20 flat has a line contact with rounded ends. This greater area and=20 single curvature allows it to take much higher loads than a ball of the same= =20 radius, material and heat treatment. You can use ball bearings in a bicycle=20 wheel. You have to use roller bearings in a lorry wheel.
 
    Regards,
 
    Chris Chapman
Subject: Paper Mate on a stick From: tchannel1@............ Date: Wed, 14 Nov 2007 09:45:06 -0700 Hi Folks, I did record the 7.7M This AM. It is visible but not = impressive, which lead me to a question. Why was it inferior? The = idea of a ball hanging from a magnet is good, the period is about 1.5 = seconds? this should be okay. The coil and magnets are okay. The only = defect I could see is that the pendulum was free to move in a circle, = and not forced to move across the wraps. I would welcome your = opinions, we learn a lot from failures. So if I can pin point why this = was an inferior set up and recording if would be helpful in new designs. When I finish the recordings I will post it on PSN as TCIDPM Ted = Channel Idaho/Paper Mate. Thanks, Ted
Hi Folks,   I did record the = 7.7M This=20 AM.   It is visible but not impressive, which lead me to a=20 question.  Why was it inferior?   The idea of a ball = hanging from=20 a magnet is good, the period is about 1.5 seconds? this should be = okay. =20 The coil and magnets are okay.   The only defect I could see = is that=20 the pendulum was free to move in a circle, and not forced to move across = the=20 wraps.   I would welcome your opinions, we learn a lot from=20 failures.   So if I can pin point why this was an inferior set = up and=20 recording if would be helpful in new designs.
When I finish the recordings I will = post it on PSN=20 as TCIDPM   Ted Channel Idaho/Paper Mate.
 
Thanks, Ted
Subject: Period formula From: tchannel1@............ Date: Wed, 14 Nov 2007 12:12:33 -0700 Hi All, I have a formula to find T Could someone help me with a = formula to find L ? Linda has a excel program so I can put in the Length of a pendulum and = the program then give the Period. I would like to add a formula, so I could put in the Period and it would = give me the pendulum length. I am not good at math, so perhaps your could also send an example. Thanks, Ted
Hi All,  I have a formula to find=20 T     Could someone help me with a formula to find=20 L ?
 
Linda has a excel program so I can put = in the=20 Length of a pendulum and the program then give the Period.
I would like to add a formula, so = I could put=20 in the Period and it would give me the pendulum length.
 
I am not good at math, so perhaps your = could also=20 send an example.
 
Thanks, Ted
Subject: Re: Paper Mate on a stick From: ChrisAtUpw@....... Date: Wed, 14 Nov 2007 14:21:56 EST In a message dated 14/11/2007, tchannel1@............ writes: Hi Folks, I did record the 7.7M This AM. It is visible but not impressive, which lead me to a question. Why was it inferior? The idea of a ball hanging from a magnet is good, the period is about 1.5 seconds? this should be okay. The coil and magnets are okay. The only defect I could see is that the pendulum was free to move in a circle, and not forced to move across the wraps. I would welcome your opinions, we learn a lot from failures. So if I can pin point why this was an inferior set up and recording if would be helpful in new designs. Hi Ted, If the arm is about 36" long and the end has the main mass, the period should be 1.8 to 1.9 seconds. If you stuck a wood T to the top of the dowel, you could mount two pens on it, but stick them to opposite ends of the same support magnet. This would give a ~constant direction of swing. The plating on the Neo magnets is Nickel. I wouldn't expect it to last very long in contact with a moving ball. When the plating wears through, the Neo magnet will start to corrode rapidly. You would be better attaching small pieces of SS razor blade to the magnet to provide a very hard contact surface. I presume that the two magnets have N and S faces with the joint at right angles to the swing direction? What are the dimensions of the coil? Regards, Chris Chapman
In a message dated 14/11/2007, tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Folks,   I did record the 7.= 7M This=20 AM.   It is visible but not impressive, which lead me to a=20 question.  Why was it inferior?   The idea of a ball hangin= g=20 from a magnet is good, the period is about 1.5 seconds? this should be=20 okay.  The coil and magnets are okay.   The only defect I c= ould=20 see is that the pendulum was free to move in a circle, and not forced to m= ove=20 across the wraps.   I would welcome your opinions, we learn a lo= t=20 from failures.   So if I can pin point why this was an inferior=20= set=20 up and recording if would be helpful in new=20 designs.
Hi Ted,
 
    If the arm is about 36" long and the=20= end=20 has the main mass, the period should be 1.8 to 1.9 seconds.
 
    If you stuck a wood T to the top of the dowel,=20= you=20 could mount two pens on it, but stick them to opposite ends of the same supp= ort=20 magnet. This would give a ~constant direction of swing.
 
    The plating on the Neo magnets is Nickel.=20 I wouldn't expect it to last very long in contact with a moving ball. W= hen=20 the plating wears through, the Neo magnet will start to corrode rapidly= ..=20 You would be better attaching small pieces of SS razor blade to the mag= net=20 to provide a very hard contact surface.  
 
    I presume that the two magnets have N and S fac= es=20 with the joint at right angles to the swing direction?
 
    What are the dimensions of the coil?
 
    Regards,
 
    Chris Chapman
Subject: Re: Period formula From: "Jerry Payton" gpayton880@....... Date: Wed, 14 Nov 2007 13:28:42 -0600 Hi Ted and All, This website that I just found gives useful formulas: http://www.ajdesigner.com/phppendulum/simple_pendulum_equation_period.php Jerry ----- Original Message ----- From: tchannel1@............ To: psn Sent: Wednesday, November 14, 2007 1:12 PM Subject: Period formula Hi All, I have a formula to find T Could someone help me with a formula to find L ? Linda has a excel program so I can put in the Length of a pendulum and the program then give the Period. I would like to add a formula, so I could put in the Period and it would give me the pendulum length. I am not good at math, so perhaps your could also send an example. Thanks, Ted
Hi Ted and All,
 
This website that I just found gives useful formulas:   = http://www.ajdesigner.com/phppendulum/simple_pendulum_equation_= period.php
Jerry
 
----- Original Message -----=20
From: tchannel1@............
To: psn
Sent: Wednesday, November 14, 2007 1:12 PM
Subject: Period formula

Hi All,  I have a formula to find=20 T     Could someone help me with a formula to find=20 L ?
 
Linda has a excel program so I can put = in the=20 Length of a pendulum and the program then give the Period.
I would like to add a formula, so = I could put=20 in the Period and it would give me the pendulum length.
 
I am not good at math, so perhaps your = could also=20 send an example.
 
Thanks, Ted
Subject: Re: Period formula From: tchannel1@............ Date: Wed, 14 Nov 2007 14:14:59 -0700 Great Jerry, This is nice find, Thanks, Ted ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Wednesday, November 14, 2007 12:28 PM Subject: Re: Period formula Hi Ted and All, This website that I just found gives useful formulas: = http://www.ajdesigner.com/phppendulum/simple_pendulum_equation_period.php= Jerry ----- Original Message -----=20 From: tchannel1@............... To: psn=20 Sent: Wednesday, November 14, 2007 1:12 PM Subject: Period formula Hi All, I have a formula to find T Could someone help me with a = formula to find L ? Linda has a excel program so I can put in the Length of a pendulum and = the program then give the Period. I would like to add a formula, so I could put in the Period and it = would give me the pendulum length. I am not good at math, so perhaps your could also send an example. Thanks, Ted
Great Jerry, This is nice find, Thanks, = Ted
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Wednesday, November 14, = 2007 12:28=20 PM
Subject: Re: Period = formula

Hi Ted and All,
 
This website that I just found gives useful formulas:   = http://www.ajdesigner.com/phppendulum/simple_pendulum_equation_= period.php
Jerry
 
----- Original Message -----=20
From: tchannel1@............ =
To: psn
Sent: Wednesday, November 14, 2007 1:12 PM
Subject: Period formula

Hi All,  I have a formula to = find=20 T     Could someone help me with a formula to find = L ?
 
Linda has a excel program so I can = put in the=20 Length of a pendulum and the program then give the = Period.
I would like to add a formula, = so I could=20 put in the Period and it would give me the pendulum = length.
 
I am not good at math, so perhaps = your could also=20 send an example.
 
Thanks, = Ted
Subject: Re: Digest from 11/14/2007 00:00:00 From: "Randy" rpratt@............. Date: Thu, 15 Nov 2007 13:17:45 -0600 > ------=_NextPart_000_003F_01C826A3.09FE13B0 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > Hi Folks, I did record the 7.7M This AM. It is visible but not = > impressive, which lead me to a question. Why was it inferior? The = > idea of a ball hanging from a magnet is good, the period is about 1.5 = > seconds? this should be okay. The coil and magnets are okay. The only = > defect I could see is that the pendulum was free to move in a circle, = > and not forced to move across the wraps. I would welcome your = > opinions, we learn a lot from failures. So if I can pin point why this = > was an inferior set up and recording if would be helpful in new designs. > When I finish the recordings I will post it on PSN as TCIDPM Ted = > Channel Idaho/Paper Mate. > > Thanks, Ted Ted, I got the impression from your description that your magnet swings above or within the coil. If you can orient the coil so the magnet swings into and out of the coil you will see much better signal. Is there a picture posted? Randy __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Earthquake pattern in Chile From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 16 Nov 2007 07:21:24 +0000 Hi all I have been looking over the earthquake pattern in Chile since the Mw7.7 earthquake. It looks like that the area is in for at least one Mw8.0+ earthquake soon. Given that there was a Mw8.0 earthquake in Peru few months back. This conlusion of mine did get reinfoced by the Mw6.7 earthquake tonight (03:12 GMT, 16.11.2007). It is hard to tell exacly when the Mw8.0+ earthquake might happen and where. We are just going to have to wait and see what happens. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake pattern in Chile From: tchannel1@............ Date: Fri, 16 Nov 2007 07:08:11 -0700 Hi Jon, Thanks for your observation. You are in a location with enough activity to have a good feel for these things. Another area I am watching, and waiting for, is Alaska. Don't know why but sometimes these South American's event are followed by other events further North, and Alaska has been quiet for sometime now. From my recordable event, Oct was uncommonly quiet and the first two weeks of Nov. Perhaps these recent earthquakes is the start of more things to come. No one has a crystal ball, but the recording and logging of past occurrences do follow averages, which tend to repeat. So Jerry in Arkansan, don't unplug your sensor. Cheers, Ted ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Friday, November 16, 2007 12:21 AM Subject: Earthquake pattern in Chile Hi all I have been looking over the earthquake pattern in Chile since the Mw7.7 earthquake. It looks like that the area is in for at least one Mw8.0+ earthquake soon. Given that there was a Mw8.0 earthquake in Peru few months back. This conlusion of mine did get reinfoced by the Mw6.7 earthquake tonight (03:12 GMT, 16.11.2007). It is hard to tell exacly when the Mw8.0+ earthquake might happen and where. We are just going to have to wait and see what happens. Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Thermal Control for Sensors From: "Jerry Payton" gpayton880@....... Date: Fri, 16 Nov 2007 11:12:24 -0600 I am searching for wiring details for using Aluminum Housed Wirewound Power Resistors used for thermal control inside an insulated housing for the seismic sensors. It has been suggested wiring several such resistors in series to accomplish a 10-30 watts from the 110v AC house supply source. I'm a little leery about the house current for safety reasons and possible AC hum. In studying the Mouser Electronics catalog, I can find several possible configurations using one to several resistors in series. The resistors specify their wattage capability, but have different resistance values to choose from. If anyone has done this and has specific values etc., I'd appreciate hearing from you. Light bulbs attract bugs and other unwanted critters! Thank you, Jerry
I am searching for wiring details for using = Aluminum=20 Housed Wirewound Power Resistors used for thermal control = inside an=20 insulated housing for the seismic sensors.  It has been suggested = wiring=20 several such resistors in series to accomplish a 10-30 watts from the = 110v AC=20 house supply source.  I'm a little leery about the house current = for safety=20 reasons and possible AC hum.
 
In studying the Mouser Electronics catalog, I can find several = possible=20 configurations using one to several resistors in series.  The=20 resistors specify their wattage capability, but have different = resistance=20 values to choose from.
 
If anyone has done this and has specific values etc., I'd = appreciate=20 hearing from you.
 
Light bulbs attract bugs and other unwanted critters!
 
Thank you,
Jerry
Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Fri, 16 Nov 2007 14:52:32 EST In a message dated 16/11/2007, gpayton880@....... writes: I am searching for wiring details for using Aluminum Housed Wirewound Power Resistors used for thermal control inside an insulated housing for the seismic sensors. It has been suggested wiring several such resistors in series to accomplish a 10-30 watts from the 110v AC house supply source. I'm a little leery about the house current for safety reasons and possible AC hum. In studying the Mouser Electronics catalog, I can find several possible configurations using one to several resistors in series. The resistors specify their wattage capability, but have different resistance values to choose from.
In a message dated 16/11/2007, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I am searching for wiring details for using=20 Aluminum Housed Wirewound Power Resistors used for therma= l=20 control inside an insulated housing for the seismic sensors.  It has=20= been=20 suggested wiring several such resistors in series to accomplish a 10-30 wa= tts=20 from the 110v AC house supply source.  I'm a little leery about the h= ouse=20 current for safety reasons and possible AC hum.
 
In studying the Mouser Electronics catalog, I can find several possib= le=20 configurations using one to several resistors in series.  The=20 resistors specify their wattage capability, but have different resist= ance=20 values to choose from.
 
Subject: Re: Thermal Control for Sensors From: Pete Rowe ptrowe@......... Date: Fri, 16 Nov 2007 11:53:15 -0800 (PST) Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wort and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P= Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power > Resistors used for thermal control inside an > insulated housing for the > seismic sensors. It has been suggested wiring > several such resistors in > series to accomplish a 10-30 watts from the 110v AC > house supply source. > I'm a little leery about the house current for > safety reasons and possible > AC hum. > > In studying the Mouser Electronics catalog, I can > find several possible > configurations using one to several resistors in > series. The resistors > specify their wattage capability, but have different > resistance values to > choose from. > > If anyone has done this and has specific values > etc., I'd appreciate hearing > from you. > > Light bulbs attract bugs and other unwanted > critters! > > Thank you, > Jerry > ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Thermal Control for Sensors From: "Jerry Payton" gpayton880@....... Date: Fri, 16 Nov 2007 14:38:44 -0600 Thanks for the info, Pete. I am not wanting so much for temperature "regulation" as I am "stability." The sensor will live in an unheated detached garage in NW Arkansas. It has quite a range of temperatures during the day and night periods, plus the seasonal changes. Last year, with a different sensor, I used a light bulb, 1/2" thick insulation board and had to throw a blanket over all that for any stability. I am going to use a thicker material this time and was checking my options. Thanks again, Jerry ----- Original Message ----- From: Pete Rowe To: psn-l@.............. Sent: Friday, November 16, 2007 1:53 PM Subject: Re: Thermal Control for Sensors Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wart and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P= Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power > Resistors used for thermal control inside an > insulated housing for the > seismic sensors. It has been suggested wiring > several such resistors in > series to accomplish a 10-30 watts from the 110v AC > house supply source. > I'm a little leery about the house current for > safety reasons and possible > AC hum. > > In studying the Mouser Electronics catalog, I can > find several possible > configurations using one to several resistors in > series. The resistors > specify their wattage capability, but have different > resistance values to > choose from. > > If anyone has done this and has specific values > etc., I'd appreciate hearing > from you. > > Light bulbs attract bugs and other unwanted > critters! > > Thank you, > Jerry > ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Thanks for the info, Pete.  I am not wanting so much for = temperature=20 "regulation" as I am "stability."   The sensor will live in an = unheated detached garage in NW Arkansas.  It has quite a range=20 of temperatures during the day and night periods, plus the seasonal = changes.  Last year, with a different sensor, I used a light bulb, = 1/2"=20 thick insulation board and had to throw a blanket over all that for any=20 stability.
 
I am going to use a thicker material this time and was checking my=20 options.
Thanks again,
Jerry
 
 
----- Original Message -----=20
From: Pete Rowe =
Sent: Friday, November 16, 2007 1:53 PM
Subject: Re: Thermal Control for Sensors

Hi Jerry
Since we don't know how well your insulation = works,=20 it
is hard to define how many watts you need to dissipate
to keep = the=20 inside of the box at a certain
temperature. I doubt that you need = even 10=20 watts if
your insulation is good. I would start with some
simple=20 experiments. You'll need a thermometer inside
the box that you can = read from=20 the outside without
opening the box. Most any inexpensive=20 indoor/outdoor
thermometers will be fine. Be aware that most of=20 those
thermometers are only accurate to +/- 2 degrees C. For
this=20 measurement that is ok.
Then get a 1 amp 12 volt DC wall wart and a = 150 ohm=20 5
or 10 watt resistor. Put the resistor in your box and
hook up = the 12=20 volts to it. The resistor will
dissipate about 1 watt (P=3D = Esquared/R). Let it=20 run for
a day and see if the temperature in the box goes up
and = levels=20 off. If this temp is ok, then you're done.
If you need more watts, = calculate=20 different resistors
for 2  or 5 watts and repeat the experiment. = You
should find that you don't need a thermostat if you
sneak up = on a=20 fixed power dissipation that keeps the
temperature stable. If your = insulation=20 is very poor or
the outside temperature has large swings, then = you'll
need=20 more watts and a thermostat to cycle the heater.
It is best to avoid=20 thermostats because they always
make electrical noise.
I hope this = helps.
Pete Rowe
--- Jerry Payton <gpayton880@.......> = wrote:

> I=20 am searching for wiring details for using Aluminum
> Housed = Wirewound=20 Power
> Resistors used for thermal control inside an
> = insulated=20 housing for the
> seismic sensors.  It has been suggested=20 wiring
> several such resistors in
> series to accomplish a = 10-30=20 watts from the 110v AC
> house supply source.
> I'm a = little leery=20 about the house current for
> safety reasons and possible
> = AC=20 hum.
>
> In studying the Mouser Electronics catalog, I = can
>=20 find several possible
> configurations using one to several = resistors=20 in
> series.  The resistors
> specify their wattage=20 capability, but have different
> resistance values to
> = choose=20 from.
>
> If anyone has done this and has specific = values
>=20 etc., I'd appreciate hearing
> from you.
>
> Light = bulbs=20 attract bugs and other unwanted
> critters!
>
> Thank = you,
> Jerry
> =



     =20 _________________________________________________________________________= ___________
Be=20 a better sports nut!  Let your teams follow you
with Yahoo = Mobile. Try=20 it now.  http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ=
__________________________________________________________

Pub= lic=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Fri, 16 Nov 2007 17:03:02 EST In a message dated 16/11/2007 17:12:39 GMT Standard Time, gpayton880@....... writes: I am searching for wiring details for using Aluminum Housed Wirewound Power Resistors used for thermal control inside an insulated housing for the seismic sensors. It has been suggested wiring several such resistors in series to accomplish a 10-30 watts from the 110v AC house supply source. I'm a little leery about the house current for safety reasons and possible AC hum. In studying the Mouser Electronics catalog, I can find several possible configurations using one to several resistors in series. The resistors specify their wattage capability, but have different resistance values to choose from.
In a message dated 16/11/2007 17:12:39 GMT Standard Time,=20 gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I am searching for wiring details for using=20 Aluminum Housed Wirewound Power Resistors used for therma= l=20 control inside an insulated housing for the seismic sensors.  It has=20= been=20 suggested wiring several such resistors in series to accomplish a 10-30 wa= tts=20 from the 110v AC house supply source.  I'm a little leery about the h= ouse=20 current for safety reasons and possible AC hum.
 
In studying the Mouser Electronics catalog, I can find several possib= le=20 configurations using one to several resistors in series.  The=20 resistors specify their wattage capability, but have different resist= ance=20 values to choose from.
 
Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Fri, 16 Nov 2007 17:49:30 EST In a message dated 16/11/2007, gpayton880@....... writes: I am searching for wiring details for using Aluminum Housed Wirewound Power Resistors used for thermal control inside an insulated housing for the seismic sensors. It has been suggested wiring several such resistors in series to accomplish a 10-30 watts from the 110v AC house supply source. I'm a little leery about the house current for safety reasons and possible AC hum. Hi Jerry, Put a sheet of Al inside the top of the box, bolt the resistors to it and earth the sheet. There should be no problems. The Al sheet spreads the heat over the top of the inside of the case and keeps the resistors cool. What you definitely DON'T want is a very hot resistor generating a heat plume which stirs up the rest of the air. You can buy a digital electronic thermometer with two sensors for about $20 See Extech from Mouser. One sensor is on an extension lead. You put this inside the top of the case / on the seismometer and leave the thermometer case in the air outside. Radioshack also sell thermometers, but don't get a radio one. They may not work all that well from inside an Al screened box. In studying the Mouser Electronics catalog, I can find several possible configurations using one to several resistors in series. The resistors specify their wattage capability, but have different resistance values to choose from. I would be inclined to use Arcol 10 W resistors in parallel. 2.2K at 110V = 5.5W, 1.5K at 110V = 8W You will certainly need at least 5 W for a Lehman size case, probably quite a lot more. I recommend the use of an electronic Max/Min thermometer. The conditions vary so much between locations that you need to actually measure of what is happening inside your box. If you can't get adequate regulation - there are still large temperature variations - try folding a single large sheet of bubblewrap over the whole case with the bubbles on the inside. You may need to put the extension sensor on the ground under the seismometer to check the actual ground variations. You can also put polystyrene sheet over the ground for a foot or more outside the seismometer case to reduce ground temperature variations - the seismometer then follows the subsoil temperature more closely. Regards, Chris Chapman
In a message dated 16/11/2007, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I am searching for wiring details for using=20 Aluminum Housed Wirewound Power Resistors used for therma= l=20 control inside an insulated housing for the seismic sensors.  It has=20= been=20 suggested wiring several such resistors in series to accomplish a 10-30 wa= tts=20 from the 110v AC house supply source.  I'm a little leery about the h= ouse=20 current for safety reasons and possible AC hum.
 Hi Jerry,
 
    Put a sheet of Al inside the top of the box, bo= lt=20 the resistors to it and earth the sheet. There should be no problems. The Al= =20 sheet spreads the heat over the top of the inside of the case and keeps the=20 resistors cool. What you definitely DON'T want is a very hot resistor=20 generating a heat plume which stirs up the rest of the air.
    You can buy a digital electronic thermometer wi= th=20 two sensors for about $20 See Extech from Mouser. One sensor is on an extens= ion=20 lead. You put this inside the top of the case / on the seismometer and leave= the=20 thermometer case in the air outside. Radioshack also sell thermometers, but=20 don't get a radio one. They may not work all that well=20 from inside an Al screened box. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
In studying the Mouser Electronics catalog, I can find several possib= le=20 configurations using one to several resistors in series.  The=20 resistors specify their wattage capability, but have different resist= ance=20 values to choose from.
    I would be inclined to use Arcol 10 W resistors= in=20 parallel. 2.2K at 110V =3D 5.5W, 1.5K at 110V =3D 8W You will certainly need= at=20 least 5 W for a Lehman size case, probably quite a lot more.
    I recommend the use of an electronic Max/Min=20 thermometer. The conditions vary so much between locations that you need to=20 actually measure of what is happening inside your box. If you can't get adeq= uate=20 regulation - there are still large temperature variations - try folding= a=20 single large sheet of bubblewrap over the whole case with the bubbles on the= =20 inside. You may need to put the extension sensor on the ground under the=20 seismometer to check the actual ground variations. You can also put=20 polystyrene sheet over the ground  for a foot or more outside the=20 seismometer case to reduce ground temperature variations - the=20 seismometer then follows the subsoil temperature more closely.  
 
    Regards,
 
    Chris Chapman
Subject: speaker magnet design From: tchannel1@............ Date: Sat, 17 Nov 2007 09:05:29 -0700 Hi All, Some time ago someone tried to explain to me how a speaker = magnet was laid out. I was referred to a wed site which had a diagram. = I lost all of that when my computer died. I want to make a new coil based on that concept. The coil is wrapped = around a cylinder. The magnets are ring magnets (stacked) which are = connected to a metal sleeve which moves over the OD of the coil. A rod = or the ring magnets themselves moves over the ID of the coil. If someone know of a picture or diagram, that, would help me. Thanks, Ted
Hi All,  Some time ago someone = tried to=20 explain to me how a speaker magnet was laid out.  I was referred to = a wed=20 site which had a diagram.   I lost all of that when my = computer=20 died.
 
I want to make a new coil based on that = concept.   The coil is wrapped around a cylinder.  The = magnets=20 are ring magnets (stacked) which are connected to a metal sleeve which = moves=20 over the OD of the coil.  A rod  or the ring magnets = themselves moves=20 over the ID of the coil.
 
If someone know of a picture or = diagram, that,=20 would help me.
 
Thanks,
Ted
 
 
Subject: Re: Thermal Control for Sensors From: "Jerry Payton" gpayton880@....... Date: Sat, 17 Nov 2007 10:15:49 -0600 Hi Pete, Chris and Others, I failed to mention that my goal is for three instrument covers. IDEA: How about an inexpensive 12v battery charger, with a sufficient max current rating, wired to three separate 15 ohm 25w resistors mounted on an aluminum plate for proper heat dissipation? If my math is right, that would be about 10 watts to each cover and a total of about 2.4 amps current demand on the charger Jerry. ----- Original Message ----- From: Pete Rowe To: psn-l@.............. Sent: Friday, November 16, 2007 1:53 PM Subject: Re: Thermal Control for Sensors Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wart and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P= Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power > Resistors used for thermal control inside an > insulated housing for the > seismic sensors. It has been suggested wiring > several such resistors in > series to accomplish a 10-30 watts from the 110v AC > house supply source. > I'm a little leery about the house current for > safety reasons and possible > AC hum. > > In studying the Mouser Electronics catalog, I can > find several possible > configurations using one to several resistors in > series. The resistors > specify their wattage capability, but have different > resistance values to > choose from. > > If anyone has done this and has specific values > etc., I'd appreciate hearing > from you. > > Light bulbs attract bugs and other unwanted > critters! > > Thank you, > Jerry > ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Hi Pete, Chris and Others,
 
I failed to mention that my goal is for three instrument = covers.
 
IDEA:   How about an inexpensive 12v battery = charger, with=20 a sufficient max current rating, wired to three separate 15 ohm 25w = resistors mounted on an aluminum plate for proper heat = dissipation? 
 
If my math is right, that would be about 10 watts to each cover and = a total=20 of about 2.4 amps current demand on the charger
 
Jerry.
 
 
----- Original Message -----=20
From: Pete Rowe =
Sent: Friday, November 16, 2007 1:53 PM
Subject: Re: Thermal Control for Sensors

Hi Jerry
Since we don't know how well your insulation = works,=20 it
is hard to define how many watts you need to dissipate
to keep = the=20 inside of the box at a certain
temperature. I doubt that you need = even 10=20 watts if
your insulation is good. I would start with some
simple=20 experiments. You'll need a thermometer inside
the box that you can = read from=20 the outside without
opening the box. Most any inexpensive=20 indoor/outdoor
thermometers will be fine. Be aware that most of=20 those
thermometers are only accurate to +/- 2 degrees C. For
this=20 measurement that is ok.
Then get a 1 amp 12 volt DC wall wart and a = 150 ohm=20 5
or 10 watt resistor. Put the resistor in your box and
hook up = the 12=20 volts to it. The resistor will
dissipate about 1 watt (P=3D = Esquared/R). Let it=20 run for
a day and see if the temperature in the box goes up
and = levels=20 off. If this temp is ok, then you're done.
If you need more watts, = calculate=20 different resistors
for 2  or 5 watts and repeat the experiment. = You
should find that you don't need a thermostat if you
sneak up = on a=20 fixed power dissipation that keeps the
temperature stable. If your = insulation=20 is very poor or
the outside temperature has large swings, then = you'll
need=20 more watts and a thermostat to cycle the heater.
It is best to avoid=20 thermostats because they always
make electrical noise.
I hope this = helps.
Pete Rowe
--- Jerry Payton <gpayton880@.......> = wrote:

> I=20 am searching for wiring details for using Aluminum
> Housed = Wirewound=20 Power
> Resistors used for thermal control inside an
> = insulated=20 housing for the
> seismic sensors.  It has been suggested=20 wiring
> several such resistors in
> series to accomplish a = 10-30=20 watts from the 110v AC
> house supply source.
> I'm a = little leery=20 about the house current for
> safety reasons and possible
> = AC=20 hum.
>
> In studying the Mouser Electronics catalog, I = can
>=20 find several possible
> configurations using one to several = resistors=20 in
> series.  The resistors
> specify their wattage=20 capability, but have different
> resistance values to
> = choose=20 from.
>
> If anyone has done this and has specific = values
>=20 etc., I'd appreciate hearing
> from you.
>
> Light = bulbs=20 attract bugs and other unwanted
> critters!
>
> Thank = you,
> Jerry
> =



     =20 _________________________________________________________________________= ___________
Be=20 a better sports nut!  Let your teams follow you
with Yahoo = Mobile. Try=20 it now.  http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ=
__________________________________________________________

Pub= lic=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Thermal Control for Sensors From: "Dewayne" n0ssy@........... Date: Sat, 17 Nov 2007 10:14:30 -0700 I haven't been reading all the post about this topic, so this may have = already been suggested My vault is very simple. It's cardboard box that is covered with 2" = Styrofoam. For thermal control I have 3 one gallon glass bottles(wide = mouth) in the vault. In one of the bottles I have placed a aquarium heater and set the temp to about 70degs. The other bottles = act as a thermal mass. Don't know if this is helpful or not. Dewayne ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Saturday, November 17, 2007 9:15 AM Subject: Re: Thermal Control for Sensors Hi Pete, Chris and Others, I failed to mention that my goal is for three instrument covers. IDEA: How about an inexpensive 12v battery charger, with a = sufficient max current rating, wired to three separate 15 ohm 25w = resistors mounted on an aluminum plate for proper heat dissipation? =20 If my math is right, that would be about 10 watts to each cover and a = total of about 2.4 amps current demand on the charger Jerry. ----- Original Message -----=20 From: Pete Rowe=20 To: psn-l@................. Sent: Friday, November 16, 2007 1:53 PM Subject: Re: Thermal Control for Sensors Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wart and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P=3D Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power=20 > Resistors used for thermal control inside an > insulated housing for the=20 > seismic sensors. It has been suggested wiring > several such resistors in=20 > series to accomplish a 10-30 watts from the 110v AC > house supply source.=20 > I'm a little leery about the house current for > safety reasons and possible=20 > AC hum. >=20 > In studying the Mouser Electronics catalog, I can > find several possible=20 > configurations using one to several resistors in > series. The resistors=20 > specify their wattage capability, but have different > resistance values to=20 > choose from. >=20 > If anyone has done this and has specific values > etc., I'd appreciate hearing=20 > from you. >=20 > Light bulbs attract bugs and other unwanted > critters! >=20 > Thank you, > Jerry=20 >=20 = _________________________________________________________________________= ___________ Be a better sports nut! Let your teams follow you=20 with Yahoo Mobile. Try it now. = http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with=20 the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information.
I haven't been reading all the post = about this=20 topic, so this may have already been suggested
 
My vault is very simple. It's cardboard = box that is=20 covered with 2" Styrofoam. For thermal control I have 3 one gallon glass = bottles(wide mouth) in the vault. In one of the bottles I have=20 placed
a aquarium heater and set the temp to = about 70degs.=20 The other bottles act as a thermal mass.
 
Don't know if this is helpful or = not.
 
Dewayne
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Saturday, November 17, = 2007 9:15=20 AM
Subject: Re: Thermal Control = for=20 Sensors

Hi Pete, Chris and Others,
 
I failed to mention that my goal is for three instrument = covers.
 
IDEA:   How about an inexpensive 12v battery = charger, with=20 a sufficient max current rating, wired to three separate 15 ohm = 25w=20 resistors mounted on an aluminum plate for proper heat = dissipation? =20
 
If my math is right, that would be about 10 watts to each cover = and a=20 total of about 2.4 amps current demand on the charger
 
Jerry.
 
 
----- Original Message -----=20
From: Pete = Rowe
Sent: Friday, November 16, 2007 1:53 PM
Subject: Re: Thermal Control for Sensors

Hi Jerry
Since we don't know how well your = insulation works,=20 it
is hard to define how many watts you need to dissipate
to = keep the=20 inside of the box at a certain
temperature. I doubt that you need = even 10=20 watts if
your insulation is good. I would start with some
simple = experiments. You'll need a thermometer inside
the box that you can = read=20 from the outside without
opening the box. Most any inexpensive=20 indoor/outdoor
thermometers will be fine. Be aware that most of=20 those
thermometers are only accurate to +/- 2 degrees C. = For
this=20 measurement that is ok.
Then get a 1 amp 12 volt DC wall wart and a = 150 ohm=20 5
or 10 watt resistor. Put the resistor in your box and
hook up = the 12=20 volts to it. The resistor will
dissipate about 1 watt (P=3D = Esquared/R). Let=20 it run for
a day and see if the temperature in the box goes = up
and=20 levels off. If this temp is ok, then you're done.
If you need more = watts,=20 calculate different resistors
for 2  or 5 watts and repeat the = experiment. You
should find that you don't need a thermostat if=20 you
sneak up on a fixed power dissipation that keeps = the
temperature=20 stable. If your insulation is very poor or
the outside temperature = has=20 large swings, then you'll
need more watts and a thermostat to cycle = the=20 heater.
It is best to avoid thermostats because they always
make = electrical noise.
I hope this helps.
Pete Rowe
--- Jerry = Payton=20 <gpayton880@.......>=20 wrote:

> I am searching for wiring details for using=20 Aluminum
> Housed Wirewound Power
> Resistors used for = thermal=20 control inside an
> insulated housing for the
> seismic=20 sensors.  It has been suggested wiring
> several such = resistors in=20
> series to accomplish a 10-30 watts from the 110v AC
> = house=20 supply source.
> I'm a little leery about the house current = for
>=20 safety reasons and possible
> AC hum.
>
> In = studying the=20 Mouser Electronics catalog, I can
> find several possible =
>=20 configurations using one to several resistors in
> series.  = The=20 resistors
> specify their wattage capability, but have=20 different
> resistance values to
> choose from.
> =
>=20 If anyone has done this and has specific values
> etc., I'd = appreciate=20 hearing
> from you.
>
> Light bulbs attract bugs = and other=20 unwanted
> critters!
>
> Thank you,
> Jerry =
>=20



     =20 = _________________________________________________________________________= ___________
Be=20 a better sports nut!  Let your teams follow you
with Yahoo = Mobile.=20 Try it now.  http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ=
__________________________________________________________

Pub= lic=20 Seismic Network Mailing List (PSN-L)

To leave this list email = PSN-L-REQUEST@............... =20 with
the body of the message (first line only): unsubscribe
See = http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: RE: Thermal Control for Sensors From: "Keith Payea" kpayea@.............. Date: Sat, 17 Nov 2007 09:24:50 -0800 Jerry: Those chargers ARE pretty cheap power supplies. Their only downfall is voltage regulation. The output, when lightly loaded, will be a lot higher than 12 volts. Mine reads about 15.4 volts with no load, dropping to about 14 near full load. I have one of the Harbor Freight units with a couple of switches to select voltage and mode. You might need to experiment with resistor values to get what you want. The wattage changes with the square of the voltage for a given resistor. Good luck, Keith _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Jerry Payton Sent: Saturday, November 17, 2007 8:16 AM To: psn-l@.............. Subject: Re: Thermal Control for Sensors Hi Pete, Chris and Others, I failed to mention that my goal is for three instrument covers. IDEA: How about an inexpensive 12v battery charger, with a sufficient max current rating, wired to three separate 15 ohm 25w resistors mounted on an aluminum plate for proper heat dissipation? If my math is right, that would be about 10 watts to each cover and a total of about 2.4 amps current demand on the charger Jerry. ----- Original Message ----- From: Pete Rowe To: psn-l@.............. Sent: Friday, November 16, 2007 1:53 PM Subject: Re: Thermal Control for Sensors Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wart and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P= Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power > Resistors used for thermal control inside an > insulated housing for the > seismic sensors. It has been suggested wiring > several such resistors in > series to accomplish a 10-30 watts from the 110v AC > house supply source. > I'm a little leery about the house current for > safety reasons and possible > AC hum. > > In studying the Mouser Electronics catalog, I can > find several possible > configurations using one to several resistors in > series. The resistors > specify their wattage capability, but have different > resistance values to > choose from. > > If anyone has done this and has specific values > etc., I'd appreciate hearing > from you. > > Light bulbs attract bugs and other unwanted > critters! > > Thank you, > Jerry > ____________________________________________________________________________ ________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Jerry:
 
Those chargers ARE pretty cheap power = supplies. =20 Their only downfall is voltage regulation.  The output, when = lightly=20 loaded, will be a lot higher than 12 volts.  Mine reads about 15.4 = volts=20 with no load, dropping to about 14 near full load.  I have one of = the=20 Harbor Freight units with a couple of switches to select voltage and=20 mode.
 
You might need to experiment with resistor = values to get=20 what you want.  The wattage changes with the square of the voltage = for a=20 given resistor.
 
Good luck,
 
    Keith

From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of Jerry=20 Payton
Sent: Saturday, November 17, 2007 8:16 AM
To: = psn-l@..............
Subject: Re: Thermal Control for=20 Sensors

Hi Pete, Chris and Others,
 
I failed to mention that my goal is for three instrument = covers.
 
IDEA:   How about an inexpensive 12v battery = charger, with=20 a sufficient max current rating, wired to three separate 15 ohm 25w = resistors mounted on an aluminum plate for proper heat = dissipation? 
 
If my math is right, that would be about 10 watts to each cover and = a total=20 of about 2.4 amps current demand on the charger
 
Jerry.
 
 
----- Original Message -----=20
From: Pete Rowe =
Sent: Friday, November 16, 2007 1:53 PM
Subject: Re: Thermal Control for Sensors

Hi Jerry
Since we don't know how well your insulation = works,=20 it
is hard to define how many watts you need to dissipate
to keep = the=20 inside of the box at a certain
temperature. I doubt that you need = even 10=20 watts if
your insulation is good. I would start with some
simple=20 experiments. You'll need a thermometer inside
the box that you can = read from=20 the outside without
opening the box. Most any inexpensive=20 indoor/outdoor
thermometers will be fine. Be aware that most of=20 those
thermometers are only accurate to +/- 2 degrees C. For
this=20 measurement that is ok.
Then get a 1 amp 12 volt DC wall wart and a = 150 ohm=20 5
or 10 watt resistor. Put the resistor in your box and
hook up = the 12=20 volts to it. The resistor will
dissipate about 1 watt (P=3D = Esquared/R). Let it=20 run for
a day and see if the temperature in the box goes up
and = levels=20 off. If this temp is ok, then you're done.
If you need more watts, = calculate=20 different resistors
for 2  or 5 watts and repeat the experiment. = You
should find that you don't need a thermostat if you
sneak up = on a=20 fixed power dissipation that keeps the
temperature stable. If your = insulation=20 is very poor or
the outside temperature has large swings, then = you'll
need=20 more watts and a thermostat to cycle the heater.
It is best to avoid=20 thermostats because they always
make electrical noise.
I hope this = helps.
Pete Rowe
--- Jerry Payton <gpayton880@.......> = wrote:

> I=20 am searching for wiring details for using Aluminum
> Housed = Wirewound=20 Power
> Resistors used for thermal control inside an
> = insulated=20 housing for the
> seismic sensors.  It has been suggested=20 wiring
> several such resistors in
> series to accomplish a = 10-30=20 watts from the 110v AC
> house supply source.
> I'm a = little leery=20 about the house current for
> safety reasons and possible
> = AC=20 hum.
>
> In studying the Mouser Electronics catalog, I = can
>=20 find several possible
> configurations using one to several = resistors=20 in
> series.  The resistors
> specify their wattage=20 capability, but have different
> resistance values to
> = choose=20 from.
>
> If anyone has done this and has specific = values
>=20 etc., I'd appreciate hearing
> from you.
>
> Light = bulbs=20 attract bugs and other unwanted
> critters!
>
> Thank = you,
> Jerry
> =



     =20 _________________________________________________________________________= ___________
Be=20 a better sports nut!  Let your teams follow you
with Yahoo = Mobile. Try=20 it now.  http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ=
__________________________________________________________

Pub= lic=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Thermal Control for Sensors From: "Jerry Payton" gpayton880@....... Date: Sat, 17 Nov 2007 11:34:25 -0600 Yes, I have thought about take heaters in the past, but knew they were for underwater application. I had not thought about using bottles. Interesting. Thanks, Jerry ----- Original Message ----- From: Dewayne To: psn-l@.............. Sent: Saturday, November 17, 2007 11:14 AM Subject: Re: Thermal Control for Sensors I haven't been reading all the post about this topic, so this may have already been suggested My vault is very simple. It's cardboard box that is covered with 2" Styrofoam. For thermal control I have 3 one gallon glass bottles(wide mouth) in the vault. In one of the bottles I have placed a aquarium heater and set the temp to about 70degs. The other bottles act as a thermal mass. Don't know if this is helpful or not. Dewayne ----- Original Message ----- From: Jerry Payton To: psn-l@.............. Sent: Saturday, November 17, 2007 9:15 AM Subject: Re: Thermal Control for Sensors Hi Pete, Chris and Others, I failed to mention that my goal is for three instrument covers. IDEA: How about an inexpensive 12v battery charger, with a sufficient max current rating, wired to three separate 15 ohm 25w resistors mounted on an aluminum plate for proper heat dissipation? If my math is right, that would be about 10 watts to each cover and a total of about 2.4 amps current demand on the charger Jerry. ----- Original Message ----- From: Pete Rowe To: psn-l@.............. Sent: Friday, November 16, 2007 1:53 PM Subject: Re: Thermal Control for Sensors Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wart and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P= Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power > Resistors used for thermal control inside an > insulated housing for the > seismic sensors. It has been suggested wiring > several such resistors in > series to accomplish a 10-30 watts from the 110v AC > house supply source. > I'm a little leery about the house current for > safety reasons and possible > AC hum. > > In studying the Mouser Electronics catalog, I can > find several possible > configurations using one to several resistors in > series. The resistors > specify their wattage capability, but have different > resistance values to > choose from. > > If anyone has done this and has specific values > etc., I'd appreciate hearing > from you. > > Light bulbs attract bugs and other unwanted > critters! > > Thank you, > Jerry > ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information.
Yes, I have thought about take heaters in the past, but knew they = were for=20 underwater application.  I had not thought about using = bottles. =20 Interesting.
Thanks,
Jerry
 
 
----- Original Message -----=20
From: Dewayne =
Sent: Saturday, November 17, 2007 11:14 AM
Subject: Re: Thermal Control for Sensors

I haven't been reading all the post = about this=20 topic, so this may have already been suggested
 
My vault is very simple. It's cardboard = box that is=20 covered with 2" Styrofoam. For thermal control I have 3 one gallon glass = bottles(wide mouth) in the vault. In one of the bottles I have=20 placed
a aquarium heater and set the temp to = about 70degs.=20 The other bottles act as a thermal mass.
 
Don't know if this is helpful or = not.
 
Dewayne
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Saturday, November 17, = 2007 9:15=20 AM
Subject: Re: Thermal Control = for=20 Sensors

Hi Pete, Chris and Others,
 
I failed to mention that my goal is for three instrument = covers.
 
IDEA:   How about an inexpensive 12v battery = charger, with=20 a sufficient max current rating, wired to three separate 15 ohm = 25w=20 resistors mounted on an aluminum plate for proper heat = dissipation? =20
 
If my math is right, that would be about 10 watts to each cover = and a=20 total of about 2.4 amps current demand on the charger
 
Jerry.
 
 
----- Original Message -----=20
From: Pete = Rowe
Sent: Friday, November 16, 2007 1:53 PM
Subject: Re: Thermal Control for Sensors

Hi Jerry
Since we don't know how well your = insulation works,=20 it
is hard to define how many watts you need to dissipate
to = keep the=20 inside of the box at a certain
temperature. I doubt that you need = even 10=20 watts if
your insulation is good. I would start with some
simple = experiments. You'll need a thermometer inside
the box that you can = read=20 from the outside without
opening the box. Most any inexpensive=20 indoor/outdoor
thermometers will be fine. Be aware that most of=20 those
thermometers are only accurate to +/- 2 degrees C. = For
this=20 measurement that is ok.
Then get a 1 amp 12 volt DC wall wart and a = 150 ohm=20 5
or 10 watt resistor. Put the resistor in your box and
hook up = the 12=20 volts to it. The resistor will
dissipate about 1 watt (P=3D = Esquared/R). Let=20 it run for
a day and see if the temperature in the box goes = up
and=20 levels off. If this temp is ok, then you're done.
If you need more = watts,=20 calculate different resistors
for 2  or 5 watts and repeat the = experiment. You
should find that you don't need a thermostat if=20 you
sneak up on a fixed power dissipation that keeps = the
temperature=20 stable. If your insulation is very poor or
the outside temperature = has=20 large swings, then you'll
need more watts and a thermostat to cycle = the=20 heater.
It is best to avoid thermostats because they always
make = electrical noise.
I hope this helps.
Pete Rowe
--- Jerry = Payton=20 <gpayton880@.......>=20 wrote:

> I am searching for wiring details for using=20 Aluminum
> Housed Wirewound Power
> Resistors used for = thermal=20 control inside an
> insulated housing for the
> seismic=20 sensors.  It has been suggested wiring
> several such = resistors in=20
> series to accomplish a 10-30 watts from the 110v AC
> = house=20 supply source.
> I'm a little leery about the house current = for
>=20 safety reasons and possible
> AC hum.
>
> In = studying the=20 Mouser Electronics catalog, I can
> find several possible =
>=20 configurations using one to several resistors in
> series.  = The=20 resistors
> specify their wattage capability, but have=20 different
> resistance values to
> choose from.
> =
>=20 If anyone has done this and has specific values
> etc., I'd = appreciate=20 hearing
> from you.
>
> Light bulbs attract bugs = and other=20 unwanted
> critters!
>
> Thank you,
> Jerry =
>=20



     =20 = _________________________________________________________________________= ___________
Be=20 a better sports nut!  Let your teams follow you
with Yahoo = Mobile.=20 Try it now.  http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ=
__________________________________________________________

Pub= lic=20 Seismic Network Mailing List (PSN-L)

To leave this list email = PSN-L-REQUEST@............... =20 with
the body of the message (first line only): unsubscribe
See = http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Thermal Control for Sensors From: "Jerry Payton" gpayton880@....... Date: Sat, 17 Nov 2007 11:38:41 -0600 Thanks Keith, Yep, you are right. I had forgotten those facts in my calculations. However, the absolute wattage is not critical. If I can just maintain an average within "normal" operating range, I'll be happy. Thanks for reminding me. Matter of fact, I closed the Harbor fright website to read this message. Jerry ----- Original Message ----- From: Keith Payea To: psn-l@.............. Sent: Saturday, November 17, 2007 11:24 AM Subject: RE: Thermal Control for Sensors Jerry: Those chargers ARE pretty cheap power supplies. Their only downfall is voltage regulation. The output, when lightly loaded, will be a lot higher than 12 volts. Mine reads about 15.4 volts with no load, dropping to about 14 near full load. I have one of the Harbor Freight units with a couple of switches to select voltage and mode. You might need to experiment with resistor values to get what you want. The wattage changes with the square of the voltage for a given resistor. Good luck, Keith -------------------------------------------------------------------------------- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Jerry Payton Sent: Saturday, November 17, 2007 8:16 AM To: psn-l@.............. Subject: Re: Thermal Control for Sensors Hi Pete, Chris and Others, I failed to mention that my goal is for three instrument covers. IDEA: How about an inexpensive 12v battery charger, with a sufficient max current rating, wired to three separate 15 ohm 25w resistors mounted on an aluminum plate for proper heat dissipation? If my math is right, that would be about 10 watts to each cover and a total of about 2.4 amps current demand on the charger Jerry. ----- Original Message ----- From: Pete Rowe To: psn-l@.............. Sent: Friday, November 16, 2007 1:53 PM Subject: Re: Thermal Control for Sensors Hi Jerry Since we don't know how well your insulation works, it is hard to define how many watts you need to dissipate to keep the inside of the box at a certain temperature. I doubt that you need even 10 watts if your insulation is good. I would start with some simple experiments. You'll need a thermometer inside the box that you can read from the outside without opening the box. Most any inexpensive indoor/outdoor thermometers will be fine. Be aware that most of those thermometers are only accurate to +/- 2 degrees C. For this measurement that is ok. Then get a 1 amp 12 volt DC wall wart and a 150 ohm 5 or 10 watt resistor. Put the resistor in your box and hook up the 12 volts to it. The resistor will dissipate about 1 watt (P= Esquared/R). Let it run for a day and see if the temperature in the box goes up and levels off. If this temp is ok, then you're done. If you need more watts, calculate different resistors for 2 or 5 watts and repeat the experiment. You should find that you don't need a thermostat if you sneak up on a fixed power dissipation that keeps the temperature stable. If your insulation is very poor or the outside temperature has large swings, then you'll need more watts and a thermostat to cycle the heater. It is best to avoid thermostats because they always make electrical noise. I hope this helps. Pete Rowe --- Jerry Payton wrote: > I am searching for wiring details for using Aluminum > Housed Wirewound Power > Resistors used for thermal control inside an > insulated housing for the > seismic sensors. It has been suggested wiring > several such resistors in > series to accomplish a 10-30 watts from the 110v AC > house supply source. > I'm a little leery about the house current for > safety reasons and possible > AC hum. > > In studying the Mouser Electronics catalog, I can > find several possible > configurations using one to several resistors in > series. The resistors > specify their wattage capability, but have different > resistance values to > choose from. > > If anyone has done this and has specific values > etc., I'd appreciate hearing > from you. > > Light bulbs attract bugs and other unwanted > critters! > > Thank you, > Jerry > ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Thanks Keith,
 
Yep, you are right.  I had forgotten those facts in my=20 calculations.  However, the absolute wattage is not critical.  = If I=20 can just maintain an average within "normal" operating range, I'll be=20 happy.
 
Thanks for reminding me.  Matter of fact, I closed the Harbor = fright=20 website to read this message.
Jerry
 
 
----- Original Message -----=20
From: Keith Payea=20
Sent: Saturday, November 17, 2007 11:24 AM
Subject: RE: Thermal Control for Sensors

Jerry:
 
Those chargers ARE pretty cheap power = supplies. =20 Their only downfall is voltage regulation.  The output, when = lightly=20 loaded, will be a lot higher than 12 volts.  Mine reads about 15.4 = volts=20 with no load, dropping to about 14 near full load.  I have one of = the=20 Harbor Freight units with a couple of switches to select voltage and=20 mode.
 
You might need to experiment with resistor = values to get=20 what you want.  The wattage changes with the square of the voltage = for a=20 given resistor.
 
Good luck,
 
    Keith

From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of Jerry=20 Payton
Sent: Saturday, November 17, 2007 8:16 AM
To: = psn-l@..............
Subject: Re: Thermal Control for=20 Sensors

Hi Pete, Chris and Others,
 
I failed to mention that my goal is for three instrument = covers.
 
IDEA:   How about an inexpensive 12v battery = charger, with=20 a sufficient max current rating, wired to three separate 15 ohm 25w = resistors mounted on an aluminum plate for proper heat = dissipation? 
 
If my math is right, that would be about 10 watts to each cover and = a total=20 of about 2.4 amps current demand on the charger
 
Jerry.
 
 
----- Original Message -----=20
From: Pete Rowe =
Sent: Friday, November 16, 2007 1:53 PM
Subject: Re: Thermal Control for Sensors

Hi Jerry
Since we don't know how well your insulation = works,=20 it
is hard to define how many watts you need to dissipate
to keep = the=20 inside of the box at a certain
temperature. I doubt that you need = even 10=20 watts if
your insulation is good. I would start with some
simple=20 experiments. You'll need a thermometer inside
the box that you can = read from=20 the outside without
opening the box. Most any inexpensive=20 indoor/outdoor
thermometers will be fine. Be aware that most of=20 those
thermometers are only accurate to +/- 2 degrees C. For
this=20 measurement that is ok.
Then get a 1 amp 12 volt DC wall wart and a = 150 ohm=20 5
or 10 watt resistor. Put the resistor in your box and
hook up = the 12=20 volts to it. The resistor will
dissipate about 1 watt (P=3D = Esquared/R). Let it=20 run for
a day and see if the temperature in the box goes up
and = levels=20 off. If this temp is ok, then you're done.
If you need more watts, = calculate=20 different resistors
for 2  or 5 watts and repeat the experiment. = You
should find that you don't need a thermostat if you
sneak up = on a=20 fixed power dissipation that keeps the
temperature stable. If your = insulation=20 is very poor or
the outside temperature has large swings, then = you'll
need=20 more watts and a thermostat to cycle the heater.
It is best to avoid=20 thermostats because they always
make electrical noise.
I hope this = helps.
Pete Rowe
--- Jerry Payton <gpayton880@.......> = wrote:

> I=20 am searching for wiring details for using Aluminum
> Housed = Wirewound=20 Power
> Resistors used for thermal control inside an
> = insulated=20 housing for the
> seismic sensors.  It has been suggested=20 wiring
> several such resistors in
> series to accomplish a = 10-30=20 watts from the 110v AC
> house supply source.
> I'm a = little leery=20 about the house current for
> safety reasons and possible
> = AC=20 hum.
>
> In studying the Mouser Electronics catalog, I = can
>=20 find several possible
> configurations using one to several = resistors=20 in
> series.  The resistors
> specify their wattage=20 capability, but have different
> resistance values to
> = choose=20 from.
>
> If anyone has done this and has specific = values
>=20 etc., I'd appreciate hearing
> from you.
>
> Light = bulbs=20 attract bugs and other unwanted
> critters!
>
> Thank = you,
> Jerry
> =



     =20 _________________________________________________________________________= ___________
Be=20 a better sports nut!  Let your teams follow you
with Yahoo = Mobile. Try=20 it now.  http://mobile.yahoo.com/sports;_ylt=3DAt9_qDKvtAbMuh1G1SQtBI7ntAcJ=
__________________________________________________________

Pub= lic=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Sat, 17 Nov 2007 13:08:46 EST In a message dated 17/11/2007, gpayton880@....... writes: I failed to mention that my goal is for three instrument covers. IDEA: How about an inexpensive 12v battery charger, with a sufficient max current rating, wired to three separate 15 ohm 25w resistors mounted on an aluminum plate for proper heat dissipation? If my math is right, that would be about 10 watts to each cover and a total of about 2.4 amps current demand on the charger Hi Jerry. You will likely find that the nominal rating that you get from battery chargers is NOT continuous. If you try to draw the maximum amount of current continuously, I doubt if it will last long and is very likely to overheat. I use resistors across the Utility Supply quite happily and I have 240 V AC. You just screw in light bulbs don't you? What are you worried about? Use a fused plug? If you want to use low voltage, buy a toroidal transformer. You need to use an Al sheet and bolt on resistors anyway. Earth the Al sheet. If you try to use ordinary high temperature wire wound resistors, the hot thermal plumes will stir up the air in the top of the box. There are plenty of cheap ways of getting this wrong. The object is to heat the air in the TOP of the box evenly so that there is a stable positive temperature gradient right down to ground level. Regards, Chris Chapman
 =20
In a message dated 17/11/2007, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I failed to mention that my goal is for three instrument covers.
 
IDEA:   How about an inexpensive 12v battery charger, = with=20 a sufficient max current rating, wired to three separate 15 ohm 25w=20 resistors mounted on an aluminum plate for proper heat dissipation? =20
 
If my math is right, that would be about 10 watts to each cover and a= =20 total of about 2.4 amps current demand on the=20 charger
Hi Jerry.
 
    You will likely find that the nominal rating th= at=20 you get from battery chargers is NOT continuous. If you try to draw the maxi= mum=20 amount of current continuously, I doubt if it will last long and is very lik= ely=20 to overheat.
 
    I use resistors across the Utility Supply quite= =20 happily and I have 240 V AC. You just screw in light bulbs don't you? What a= re=20 you worried about? Use a fused plug?
 
    If you want to use low voltage, buy a toroid= al=20 transformer.
 
    You need to use an Al sheet and bolt on resisto= rs=20 anyway. Earth the Al sheet. If you try to use ordinary high temperature wire= =20 wound resistors, the hot thermal plumes will stir up the air in the top of t= he=20 box.
    There are plenty of cheap ways of getting this=20 wrong.
 
    The object is to heat the air in the TOP of the= box=20 evenly so that there is a stable positive temperature gradient right down to= =20 ground level.
 
    Regards,
 
    Chris Chapman
Subject: coil design From: tchannel1@............ Date: Sat, 17 Nov 2007 11:19:28 -0700 Hi All, I found it: Thanks, Chris and others. = http://jclahr.com/science/psn/chapman/coil/index.html Ted
Hi All,   I found = it:   Thanks,=20 Chris and others.    http://jclahr.com= /science/psn/chapman/coil/index.html
Ted
Subject: Re: Thermal Control for Sensors From: "Jerry Payton" gpayton880@....... Date: Sat, 17 Nov 2007 12:50:50 -0600 >I use resistors across the Utility Supply quite happily and I have 240 V >AC. You just screw in light bulbs don't you? What are you worried about? >Use a fused plug? Chris, I do NOT want to appear argumentative or afraid of using anything. I do not like the idea of exposed 100v or 240v AC, in your case, loose inside the vault. I can conceive a safety factor as-well-as possible ac hum. THAT is why I am considering the DC approach. Respectfully, Jerry
>I use resistors=20 across the Utility Supply quite happily and I have 240 V AC. You just = screw in=20 light bulbs don't you? What are you worried about? Use a fused = plug?
 
Chris, I do NOT want to = appear=20 argumentative or afraid of using anything.  I do not like the = idea of=20 exposed 100v or 240v AC, in your case, loose inside the vault.  I = can=20 conceive a safety factor as-well-as possible ac hum. 
 
THAT is why I am = considering the=20 DC approach.
 
Respectfully,
Jerry
 Subject: Re: Thermal Control for Sensors From: ian ian@........... Date: Sat, 17 Nov 2007 18:53:12 +0000 I use a psu from a redundant pc Ian -- I use a psu from a redundant pc

Ian

--

Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Sat, 17 Nov 2007 16:15:19 EST In a message dated 17/11/2007, gpayton880@....... writes: I do not like the idea of exposed 100v or 240v AC, in your case, loose inside the vault. I can conceive a safety factor as-well-as possible ac hum. Hi Jerry, Entirely your choice. I use three core cable, a cable clamp and I earth the Al plate. The electrical connections are soldered to the resistors and they are completely covered with adhesive heatshrink insulation. The plug is fused. There is NO exposed wiring to touch, NO hum and it is PERFECTLY safe. Regards, Chris Chapman
In a message dated 17/11/2007, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3D"Times New Roman" color=3D#= 000000=20 size=3D3>I do not like the idea of= exposed=20 100v or 240v AC, in your case, loose inside the vault.  I can conceiv= e a=20 safety factor as-well-as possible ac hum. =20
Hi Jerry,
 
    Entirely your choice.
 
    I use three core cable, a cable clamp and=20= I=20 earth the Al plate. The electrical connections are soldered to the resistors= and=20 they are completely covered with adhesive heatshrink insulation. The plug is= =20 fused.
 
    There is NO exposed wiring to touch, NO hum and= it=20 is PERFECTLY safe.
 
    Regards,
 
    Chris Chapman
Subject: Too many sensors From: tchannel1@............ Date: Sun, 18 Nov 2007 10:59:38 -0700 Hi Folks, I have accumulated several sensors, and wish to build at = least two more. I have been in contact with several schools, and I am = in the process of helping them with additional sensors. One of the = sensors, don't know which, may go directly to one of the schools. In = the meanwhile, I am running out of room to store these things. I don't want to sell them, but I would like to recover some of, or all = of my expenses for the parts. I am in Boise Idaho, so if someone is = interested in one of them, and is close enough to pick it up or cover = the shipping we might find a new home for one or more of them. Most of you are aware of them, from the conversations, and sharing of = information over the past months. They are: 1. The Copper pipe vertical, (which I think is going to the school) 2. The Slinky 3. The Folded Pendulum 4. A primitive Lehman (no damper) not fully tested, should work? All of these have been tested, and are amplified using Larry's board, = and DataQ. These are only the sensors, not the amplifier, software or = computer. I am pleased with their performance, and all have recorded many = earthquakes, from 3's to 8's, from 60 miles to 9000 miles. I can give details on each, and pictures, if you are interested. I = think any of them could be shipped, ups.=20 You would need (the sensor), an old computer, and about $150 worth of = electronics, to get up and running. Some people are interested in this science but are limited in building = their own. This might be a way to get your own Seismic Station, at = bare bones expense. Thanks, Ted
Hi Folks,  I have accumulated = several sensors,=20 and wish to build at least two more.  I have been in contact with = several=20 schools, and I am in the process of helping them with additional=20 sensors.   One of the sensors, don't know which, may go = directly to=20 one of the schools.   In the meanwhile, I am running out of = room to=20 store these things.
 
I don't want to sell them, but I would = like to=20 recover some of, or all of my expenses for the = parts.    I=20 am in Boise Idaho, so if someone is interested in one of them, = and is close=20 enough to pick it up or cover the shipping we might find a new home for = one or=20 more of them.
 
Most of you are aware of them, from the = conversations, and sharing of information over the past = months.   They=20 are:
 
1.  The Copper pipe = vertical,  (which I=20 think is going to the school)
2.  The Slinky
3.  The Folded = Pendulum
4.  A primitive Lehman  (no = damper) not=20 fully tested, should work?
 
All of these have been tested, and are = amplified=20 using Larry's board, and DataQ.   These are only the sensors, = not the=20 amplifier, software or computer.
I am pleased with their performance, = and all have=20 recorded many earthquakes, from 3's to 8's, from 60 miles to 9000=20 miles.
I can give details on each, and = pictures, if you=20 are interested.   I  think any of them could be shipped, = ups.=20
 
You would need (the sensor), an old = computer, and=20 about $150 worth of electronics, to get up and running.
 
Some people are interested in this = science but are=20 limited in building their own.   This might be a way to get = your own=20 Seismic Station, at bare bones expense.
 
Thanks,
Ted
 
Subject: Re: Thermal Control for Sensors From: Stephen & Kathy skmort@............ Date: Sun, 18 Nov 2007 14:52:59 -0800 Small Space Heater Control. OK, I scanned a hand sketch of my house current powered, small space heater control circuit, that I use for my seismograph. Wow, that was a mouth full,, ha! Anyway, I use a 100 watt light bulb in one of those ceramic sockets, mounted to a hard plastic type box,, could be bakelite (spell)?? The original circuit was designed to control up to 25 amps and used both halves of the power cycle! I modified it to reduce parts, and power, for better price, so it only controls a half cycle and about 3 amps max, which should easily control 150 watts! In the 11 years or so of operation, I've had to change the light bulb twice! If I ever come across a low watt, screw-in heater (I think they use something like that in incubators?) I'll start using one of those! It would drive resistors for heaters, but would take tricky construction to eliminate 117 volt hazard???? As I understand the circuit, it doesn't chop the wave to control the power to the bulb. It either uses the complete half cycle, or it skips the cycle! In other words, when it needs power, it turns on at or near zero volts, thus reducing, or eliminating switching spikes! My box is set up in two layers. The seismograph is inside a cardboard box! The NTC (negative temp. coefficient) resistor (thermistor?) is inserted into the box through a small hole, with the rest of the heater and control set just outside the box. Over this, I place an insulated box. This way the seismograph is isolated from the thermal currents generated by the light bulb. It is about 3.5 ft from the sensing coil. If there is 60 hz hum, it is being effectively reduced in the filter circuit?? Lining the cardboard box with foil would probably reduce further, if needed? There have been a couple of times that the heater changed temp by a couple of degrees? I think it is related to the cheap variable resistor that sets the temp, and or the fact that I have it adjusted close to the limit of that resistor?? A few other part changes, (to put the variable resistor in the middle of its range), or replace it with a fixed resistor, (maybe even eliminate it), may make it more stable? I think the original circuit was designed for the human comfort range, so I think I'm probably at the limit, at about 93 degrees! The 10k temperature adj. resistor is probably set close to zero? I got the original circuit out of a circuit design book, but can't remember the name,, in fact, that might be the name??? Anyway I scanned it into an 80k jpeg and will be more than happy to share! The engineers in the group are more than welcome to check it for errors, or possible improvements, terminology, parts updates, etc. With minor modification, it would probably handle 220 volts AC??? Maybe even lower voltages??? Stephen PSN Station # 55 Small Space Heater Control.

OK, I scanned a hand sketch of my house current powered, small space heater control circuit, that I use for my seismograph.=A0=A0 Wow, that was a mouth full,, ha!=A0 Anyway, I use a 100 watt light bulb in one= of those ceramic sockets, mounted to a hard plastic type box,, could be bakelite (spell)??

The original circuit was designed to control up to 25 amps and used both halves of the power cycle!=A0 I modified it to reduce parts, and power, for better price, so it only controls a half cycle and about 3 amps max, which should easily control 150 watts!=A0 In the 11 years or so= of operation,=A0 I've had to change the light bulb twice!=A0=A0 If I ever= come across a low watt, screw-in heater (I think they use something like that in incubators?) I'll start using one of those!=A0=A0=A0 It woul= d drive resistors for heaters, but would take tricky construction to eliminate 117 volt hazard????

As I understand the circuit, it doesn't chop the wave to control the power to the bulb.=A0 It either uses the complete half cycle, or it skips= the cycle!=A0=A0 In other words, when it needs power, it turns on at or near zero volts, thus reducing, or eliminating switching spikes!

My box is set up in two layers.=A0=A0 The seismograph is inside a cardboa= rd box!=A0=A0 The NTC (negative temp. coefficient) resistor (thermistor?) is= inserted into the box through a small hole, with the rest of the heater and control set just outside the box.=A0=A0 Over this, I place an insulat= ed box.=A0=A0 This way the seismograph is isolated from the thermal currents= generated by the light bulb.=A0=A0 It is about 3.5 ft from the sensing coil.=A0 If there is 60 hz hum, it is being effectively reduced in the filter circuit??=A0=A0 Lining the cardboard box with foil would probably reduce further, if needed?

There have been a couple of times that the heater changed temp by a couple of degrees?=A0=A0 I think it is related to the cheap variable resistor that sets the temp, and or the fact that I have it adjusted close to the limit of that resistor??=A0=A0 A few other part changes, (to= put the variable resistor in the middle of its range), or replace it with a fixed resistor, (maybe even eliminate it), may make it more stable?=A0=A0 I think the original circuit was designed for the human comfort range, so I think I'm=A0 probably at the limit, at about 93 degrees!=A0 The 10k temperature adj. resistor is probably set close to zero?

I got the original circuit out of a circuit design book, but can't remember the name,,=A0=A0 in fact, that might be the name???=A0 Anyway I scanned it into an=A0 80k jpeg and will be more than happy to share!=A0=A0= The engineers in the group are more than welcome to check it for errors, or possible improvements, terminology, parts updates, etc.=A0 With minor modification, it would probably handle 220 volts AC???=A0 Maybe even lower voltages???

=A0 Stephen
=A0 PSN Station # 55 =A0 =A0


Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Sun, 18 Nov 2007 21:06:48 EST In a message dated 18/11/2007, skmort@............ writes: Small Space Heater Control. Hi Stephen, The problem with this is that the switch on temperature is fixed. You would be OK if you used a differential thermometer, one sensor on the ground and the other in top of the box. These could be two diodes, two Pt elements or two Si thermometer micorcircuits with an amplifier and offset control. The difference between not supplying enough heat and getting reverse convection which upsets the seismometer and providing too much heat which stirs up the air in the whole case is not that great. It depends on the ground and outside air temperatures. The easiest method is to provide a constant power to a heated Al panel and vary this until the convection just stops in your particular box. If you use the Al cased resistors bolted to an Al sheet, solder on insulated wires and cover the joints with adhesive heatshrink tube, you can get a completely safe system. It will tend to track the environmental changes fairly well and keep the top of the box just warm enough, but setting it up in the first place may take a few tests with different heater powers. Another alternative is to use a commercial energy control module, such as is provided by a light dimmer control and use this to drive your heater resistors. But these do tend to generate RFI and you may need some protection capacitors. Regards, Chris Chapman
In a message dated 18/11/2007, skmort@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DCourier color=3D#000000 siz= e=3D4>Small Space Heater=20 Control.
Hi Stephen,
 
    The problem with this is that the switch on=20 temperature is fixed. You would be OK if you used a differential thermometer= ,=20 one sensor on the ground and the other in top of the box. These could be two= =20 diodes, two Pt elements or two Si thermometer micorcircuits with an amplifie= r=20 and offset control.
    The difference between not supplying enough hea= t=20 and getting reverse convection which upsets the seismometer and providing to= o=20 much heat which stirs up the air in the whole case is not that great. It dep= ends=20 on the ground and outside air temperatures. The easiest method is to provide= a=20 constant power to a heated Al panel and vary this until the convection just=20 stops in your particular box.
    If you use the Al cased resistors bolted to an=20= Al=20 sheet, solder on insulated wires and cover the joints with adhesive=20 heatshrink tube, you can get a completely safe system. It will ten= d to=20 track the environmental changes fairly well and keep the top of the box just= =20 warm enough, but setting it up in the first place may take a few tests with=20 different heater powers.
    Another alternative is to use a commercial= =20 energy control module, such as is provided by a light dimmer control and use= =20 this to drive your heater resistors. But these do tend to generate RFI=20= and=20 you may need some protection capacitors.
 
    Regards,
 
    Chris Chapman
Subject: Re: Thermal Control for Sensors From: Stephen & Kathy skmort@............ Date: Sun, 18 Nov 2007 20:12:51 -0800 Hi Chris, Actually as I understand it, it is the switch off temp that is fixed! In other words, once the temp has reach its operational point, the control starts skipping cycles to maintain a max set temp??? I think we are talking about micro volts between on and off, which could be micro degrees, or perhaps milli degrees diff??? At any rate I'll let you and the other experts figure it out,, in the mean time, except for the two bulbs over the last 11 years and a couple of temp change bumps 5 or 6 years ago, it has been rock solid for me here in Northern Calif with winter temps to about 13 degrees F. There are a few afternoons in the summer when the temp hits 105 or so, when my system loses temp control! I could fix it by raising the temp, but it isn't critical for my interest! Others may have a more critical need! That is where you and other come in. The main reason I like this circuit is that it doesn't chop the cycle like dimmers do, so there is very little if any noise generated! Thanks for your comments, others may want to incorporate them! It is kind of a trick to discuss a circuit that hasn't been seen, ha! The circuit has a transistor controlled by the NTC that drives a low current SCR which drives a high current SCR. They get their operating voltages directly from the 117, with a 10 volt zener,, so no power supply,, simple! Stephen ChrisAtUpw@....... wrote: > In a message dated 18/11/2007, skmort@............ writes: > > Small Space Heater Control. > > Hi Stephen, > > The problem with this is that the switch on temperature is fixed. > You would be OK if you used a differential thermometer, one sensor on > the ground and the other in top of the box. These could be two diodes, > two Pt elements or two Si thermometer micorcircuits with an amplifier > and offset control. > The difference between not supplying enough heat and getting > reverse convection which upsets the seismometer and providing too much > heat which stirs up the air in the whole case is not that great. It > depends on the ground and outside air temperatures. The easiest method > is to provide a constant power to a heated Al panel and vary this > until the convection just stops in your particular box. > If you use the Al cased resistors bolted to an Al sheet, solder > on insulated wires and cover the joints with adhesive heatshrink tube, > you can get a completely safe system. It will tend to track the > environmental changes fairly well and keep the top of the box just > warm enough, but setting it up in the first place may take a few tests > with different heater powers. > Another alternative is to use a commercial energy control module, > such as is provided by a light dimmer control and use this to drive > your heater resistors. But these do tend to generate RFI and you may > need some protection capacitors. > > Regards, > > Chris Chapman Hi Chris,
Actually as I understand it, it is the switch off temp that is fixed!   In other words, once the temp has reach its operational point, the control starts skipping cycles to maintain a max set temp???  I think we are talking about micro volts between on and off, which could be micro degrees, or perhaps milli degrees diff???   At any rate I'll let you and the other experts figure it out,,   in the mean time, except for the two bulbs over the last 11 years and a couple of temp change bumps 5 or 6 years ago, it has been rock solid for me here in Northern Calif with winter temps to about 13 degrees F.   There are a few afternoons in the summer when the temp hits 105 or so, when my system loses temp control!  I could fix it by raising the temp, but it isn't critical for my interest!   Others may have a more critical need!   That is where you and other come in.

The main reason I like this circuit is that it doesn't chop the cycle like dimmers do, so there is very little if any noise generated!

Thanks for your comments, others may want to incorporate them!  It is kind of a trick to discuss a circuit that hasn't been seen, ha!   The circuit has a transistor controlled by the NTC that drives a low current SCR which drives a high current SCR.  They get their operating voltages directly from the 117, with a 10 volt zener,,  so no power supply,,  simple!
  Stephen

ChrisAtUpw@....... wrote:
In a message dated 18/11/2007, skmort@............ writes:
Small Space Heater Control.
Hi Stephen,
 
    The problem with this is that the switch on temperature is fixed. You would be OK if you used a differential thermometer, one sensor on the ground and the other in top of the box. These could be two diodes, two Pt elements or two Si thermometer micorcircuits with an amplifier and offset control.
    The difference between not supplying enough heat and getting reverse convection which upsets the seismometer and providing too much heat which stirs up the air in the whole case is not that great. It depends on the ground and outside air temperatures. The easiest method is to provide a constant power to a heated Al panel and vary this until the convection just stops in your particular box.
    If you use the Al cased resistors bolted to an Al sheet, solder on insulated wires and cover the joints with adhesive heatshrink tube, you can get a completely safe system. It will tend to track the environmental changes fairly well and keep the top of the box just warm enough, but setting it up in the first place may take a few tests with different heater powers.
    Another alternative is to use a commercial energy control module, such as is provided by a light dimmer control and use this to drive your heater resistors. But these do tend to generate RFI and you may need some protection capacitors.
 
    Regards,
 
    Chris Chapman
Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Mon, 19 Nov 2007 09:20:26 EST In a message dated 19/11/2007, skmort@............ writes: Hi Chris, Actually as I understand it, it is the switch off temp that is fixed! In other words, once the temp has reach its operational point, the control starts skipping cycles to maintain a max set temp??? Hi
In a message dated 19/11/2007, skmort@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DCourier color=3D#000000 siz= e=3D3>Hi Chris,
Actually as I understand it, it is the s= witch=20 off temp that is fixed!   In other words, once the temp has reac= h=20 its operational point, the control starts skipping cycles to maintain a ma= x=20 set temp??? 
Hi
Subject: Re: Thermal Control for Sensors From: ChrisAtUpw@....... Date: Mon, 19 Nov 2007 09:33:24 EST In a message dated 19/11/2007, skmort@............ writes: Hi Chris, Actually as I understand it, it is the switch off temp that is fixed! In other words, once the temp has reach its operational point, the control starts skipping cycles to maintain a max set temp? Hi Stephen, That is what I have assumed from your description. Say you set it up in Summer with an air temperature of 30 C. The ground temperature minimum may be 20 C, giving a comfortable temperature difference of 10 C Deg. You leave it at the same setting in the winter when the ground temperature has fallen to -5 C The heater still maintains a top temperature of 30 C, giving a differential within the case of 35 C deg instead of 10 C Deg. This is likely large enough to cause convection noise within the case. If you can supply just enough heat to follow the ground temperature fluctiations + say 10 Deg, this would be ideal. It would also use less power. Maybe you could use two thermistors? If you send me the circuit, I will have a look. Regards, Chris Chapman
In a message dated 19/11/2007, skmort@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DCourier color=3D#000000 siz= e=3D3>Hi Chris,
Actually as I understand it, it is the s= witch=20 off temp that is fixed!   In other words, once the temp has reac= h=20 its operational point, the control starts skipping cycles to maintain a ma= x=20 set temp? 
Hi Stephen,
 
    That is what I have assumed from your descripti= on.=20 Say you set it up in Summer with an air temperature of 30 C.
    The ground temperature minimum may be 20 C, giv= ing=20 a comfortable temperature difference of 10 C Deg.
 
     You leave it at the same setting in the=20 winter when the ground temperature has fallen to -5 C
    The heater still maintains a top temperature of= 30=20 C, giving a differential within the case of 35 C deg instead of 10 C Deg. Th= is=20 is likely large enough to cause convection noise within the case.
 
    If you can supply just enough heat to follow th= e=20 ground temperature fluctiations + say 10 Deg, this would be ideal. It would=20= also=20 use less power.
 
    Maybe you could use two thermistors? If you sen= d me=20 the circuit, I will have a look.
 
    Regards,
 
    Chris Chapman
Subject: WinQuake magnitude correction From: "Randy" rpratt@............. Date: Wed, 21 Nov 2007 20:16:08 -0600 Hi All, The recent activity in the Jujuy and Antofagasta areas prompted me to = try and determine a better estimate of the MI MS correction. I had = several quakes from about the same area ranging from 5.8 to over 7.7 all = within several weeks and all relatively south of my north south sensor. = As I tried to enter the correction to match published magnitudes I got = numbers from .00025 down to .00006 to make the various magnitudes match. = What type of accuracy should I expect on magnitude using a correction = like this? I used unfiltered data. Should I use a specific filter to = get a more standard read? Randy
Hi All,
 
The recent activity in the Jujuy and = Antofagasta=20 areas prompted me to try and determine a better estimate of the MI MS=20 correction.  I had several quakes from about the same area ranging = from 5.8=20 to over 7.7 all within several weeks and all relatively south of my = north south=20 sensor.  As I tried to enter the correction to match published = magnitudes I=20 got numbers from .00025 down to .00006 to make the various magnitudes=20 match.  What type of accuracy should I expect on magnitude using a=20 correction like this?  I used unfiltered data.  Should I use a = specific filter to get a more standard read?
 
Randy
Subject: ML4.4 earthquake near me From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Mon, 26 Nov 2007 19:41:45 +0000 Hi all At 15:31 today (26.11.2007) there was a ML4.4 earthquake in a area called Hveravellir (hot springs). That area is on a top of a volcano that is 75 km away from me. I would like to know if anyone with a teleseismic station did record the earthquake.=20 More information on the earthquakes can be seen here, http://hraun.vedur.is/ja/englishweb/index.html Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Increased activite warning From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Tue, 27 Nov 2007 14:06:34 +0000 Hi all The goverment body here in Iceland that issues warnings in case of a natrual desasters has just issued a warning about possiblite of more earthquakes in the West volcanic zone in Iceland. It appears that the West Volcanic zone in Iceland is getting more activie as we speak. I would like to hear from people on this matter, if possible. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Mw7.3 earthquake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 29 Nov 2007 20:02:50 +0000 Hi all At 19:00 GMT tonight there was a Mw7.3 earthquake ( preliminary size) near Leeward Islands. According to EMSC the depth of the earthquake was 153km.=20 So far I don't have heard any news about this earthquake in internatonal news. But I do expect to see news in one or two hours about it. If there was any damage in this earthquake. Here is the EMSC link. http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D71249 This earthquake was picked up by two of my stations.=20 Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: HS-10-1 questions From: "Andreas Tschammer" asensio@............ Date: Fri, 30 Nov 2007 10:12:39 +0100 Hi all, my name is Andreas Tschammer and I am from Germany. I recently bought a Geospace HS-10-1 vertical sensor (400 Ohms 3 V/ips) at ebay from=20 a German surplus dealer. I would like to do some experiments with active damping/period extension (Lennartz-Method) = http://www.lennartz-electronic.de/ and http://www.terrajp.co.jp/Seismometers.pdf (pp. 50). Today I found the time to do some tests to help me to decide whether=20 to keep it or to send it back. It was not really a bargain, so it should = work 100%. I was using a resistive bridge - as described by ST Morrissey - to check the resonance frequency and linearity. I removed the 2k2 resistor from = the terminals of the phone. The resonance was not very pronounced between 1 Hz and 2 Hz. The sine current from the function generator was about = 30-100 uA peak-peak. The up/down movement of the period adjustment screw was very = small but visible. Especially below 1 Hz the output voltage of the coil was non sinusoidal. = It looked as if=20 the mass got stuck by some kind of friction and then was released as the = current was growing. I could make a picture of the oscilloskope screen if this helps. I have a 24 Hz geophone which has always a linear/sinusoidal output = during this test.=20 The resonance is also clearly visible.=20 I am afraid the nonlinearity of the HS-10 will be a problem when I try = to LP filter the signal by software to get rid of the high frequency seismic noise. The HS-10 seems to be pretty sensitive. I have it sitting on the ground = of the basement of my house with a x100 amplifier and digital oscilloscope connected. I can see = movements all the time. It gets lower at night (15 mVpp) but still a lot of avtivity althought no cars = can be heard outside. So its not totally dead. The coil resistance is ok. I can hear some kind of klicking noise when I = move the mass by the period adjustment=20 rod slowly up and down. I am not sure whether it comes from the = astitisizing (typo?) spring or from the inside of the housing. Do you know whether this kind of non linear behaviour of the HS-10 is = normal?=20 Can you recommend any other test that can be done with normal electronic = lab=20 equipment to check the HS-10?=20 Is it possible/recommended to open the housing? I was not able to find a = way to open it. Maybe I can see the problem inside..=20 I really would like to keep the HS-10, so any kind of advise is welcome. Thank you very much in advance for your help! Andreas Tschammer Rheinbach, Germany
Hi all,
 
my name is Andreas Tschammer and I am = from Germany.=20 I recently bought
a Geospace HS-10-1 vertical sensor (400 Ohms 3 = V/ips) at=20 ebay from
a German surplus dealer. I would like to do some = experiments with=20 active
damping/period extension (Lennartz-Method) http://www.lennartz-electroni= c.de/
and =20 http://www.terrajp.co.= jp/Seismometers.pdf =20 (pp. 50).
 
Today I found the time to do some tests = to help me=20 to decide whether
to keep it or to send it back. It was = not really a=20 bargain, so it should work 100%.
I was using a resistive bridge - as=20 described by ST Morrissey - to check
the resonance frequency and = linearity. I=20 removed the 2k2 resistor from the
terminals of the phone. The = resonance was=20 not very pronounced  between
1 Hz and 2 Hz. The sine current = from the=20 function generator was about 30-100 uA
peak-peak. The up/down = movement of the=20 period adjustment screw was very small but visible.
Especially below = 1 Hz the=20 output voltage of the coil was non sinusoidal. It looked as if
the = mass got=20 stuck by some kind of friction and then was released as the current was=20 growing.
I could make a picture of the = oscilloskope screen=20 if this helps.
I have a 24 Hz geophone which has always a=20 linear/sinusoidal output during this test.
The resonance is also clearly = visible.=20
I am afraid the nonlinearity of = the HS-10 will=20 be a problem when I try to LP filter the signal by software
to get rid of the high frequency = seismic=20 noise.
The HS-10 seems to be pretty sensitive. = I have it=20 sitting on the ground of the basement of my house
with a x100 amplifier and digital = oscilloscope=20 connected. I can see movements all the time. It gets
lower at night (15 mVpp) but still = a lot of=20 avtivity althought no cars can be heard outside. So its not totally=20 dead.
The coil resistance is ok. I can hear = some kind of=20 klicking noise when I move the mass by the period adjustment =
rod slowly up and down. I am not sure = whether it=20 comes from the astitisizing (typo?) spring or from the = inside
of the housing.
 
Do you know whether this kind of non = linear=20 behaviour of the HS-10 is normal?
Can you recommend any other test = that can=20 be done with normal electronic lab
equipment to check the HS-10?=20
Is it possible/recommended to open the = housing? I=20 was not able to find a way to open it.
Maybe I can see the problem inside.. =
 
I really would like to keep the HS-10, = so any kind=20 of advise is welcome.
Thank you very much in advance for your = help!
 

Andreas Tschammer
Rheinbach, Germany
Subject: Re: HS-10-1 questions From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 30 Nov 2007 14:14:56 +0000 Hi There is a large diffrence between a geophone with 24Hz natrual frequancy and a sensor with 1Hz natrual frequancy. The clicking noise problay is the mass in the sensor hitting the end of the coil or the end of the housing. I have not worked with this type of seismometer, but I do have two 4.5Hz geophones to record earthquake. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: HS-10-1 questions From: "Jack Ivey" ivey@.......... Date: Fri, 30 Nov 2007 10:41:37 -0500 Andreas, Are you inadvertently overdriving the seismometer so it is hitting the = end stops? Seems unlikely that would happen with only 100uA through 400 ohms. What = happens when you reduce=20 your test current to 1/10 as much? The clicking noise may be normal. I have a Ranger 1-second seismometer, = and when you load and unload the spring the mass hits the end stops and makes a = clunk/click noise. Is there a centering indicator on your unit? On the ranger = there is a window with a pointer to let you get the mass centered. Although I normally take the case off anything I buy first thing, but I = would be careful=20 about disassembling an expensive seismometer apart without instructions = from the manufacturer,=20 it might require assembly tools and procedures you don't have to get it = back together. =20 Maybe others have better information. I would like to use the Lenmartz method with my Ranger, so I am = interested in=20 your future progress. Jack=20 ________________________________________ From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Andreas Tschammer Sent: Friday, November 30, 2007 4:13 AM To: PSN-L@.............. Subject: HS-10-1 questions Hi all, =A0 my name is Andreas Tschammer and I am from Germany. I recently bought a Geospace HS-10-1 vertical sensor (400 Ohms 3 V/ips) at ebay from=20 a German surplus dealer. I would like to do some experiments with active damping/period extension (Lennartz-Method) = http://www.lennartz-electronic.de/ and=A0 http://www.terrajp.co.jp/Seismometers.pdf=A0 (pp. 50). =A0 Today I found the time to do some tests to help me to decide whether=20 to keep it or to send it back. It was not really a bargain, so it should = work 100%. I was using a resistive bridge - as described by ST Morrissey - to check the resonance frequency and linearity. I removed the 2k2 resistor from = the terminals of the phone. The resonance was not very pronounced=A0 between 1 Hz and 2 Hz. The sine current from the function generator was about = 30-100 uA peak-peak. The up/down movement of the period adjustment screw was very = small but visible. Especially below 1 Hz the output voltage of the coil was non sinusoidal. = It looked as if=20 the mass got stuck by some kind of friction and then was released as the = current was growing. I could make a picture of the oscilloskope screen if this helps. I have a 24 Hz geophone which=A0has always a linear/sinusoidal = output=A0during this test.=20 The resonance=A0is also clearly visible.=20 I am afraid the nonlinearity=A0of the HS-10 will be a problem when I try = to LP filter the signal by software to get rid of the high frequency seismic noise. The HS-10 seems to be pretty sensitive. I have it sitting on the ground = of the basement of my house with a x100 amplifier and digital oscilloscope connected. I can see = movements all the time. It gets lower at night (15 mVpp)=A0but still a lot of avtivity althought no cars = can be heard outside. So its not totally dead. The coil resistance is ok. I can hear some kind of klicking noise when I = move the mass by the=A0period adjustment=20 rod slowly up and down. I am not sure whether it comes from the = astitisizing (typo?)=A0spring or from the inside of the housing. =A0 Do you know whether this kind of non linear behaviour of the HS-10 is = normal?=20 Can you recommend any other test that can be done with normal electronic = lab=20 equipment to check the HS-10?=20 Is it possible/recommended to open the housing? I was not able to find a = way to open it. Maybe I can see the problem inside..=20 =A0 I really would like to keep the HS-10, so any kind of advise is welcome. Thank you very much in advance for your help! =A0 Andreas Tschammer Rheinbach, Germany __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: HS-10-1 questions From: "Jack Ivey" ivey@.......... Date: Fri, 30 Nov 2007 10:41:37 -0500 Andreas, Are you inadvertently overdriving the seismometer so it is hitting the = end stops? Seems unlikely that would happen with only 100uA through 400 ohms. What = happens when you reduce=20 your test current to 1/10 as much? The clicking noise may be normal. I have a Ranger 1-second seismometer, = and when you load and unload the spring the mass hits the end stops and makes a = clunk/click noise. Is there a centering indicator on your unit? On the ranger = there is a window with a pointer to let you get the mass centered. Although I normally take the case off anything I buy first thing, but I = would be careful=20 about disassembling an expensive seismometer apart without instructions = from the manufacturer,=20 it might require assembly tools and procedures you don't have to get it = back together. =20 Maybe others have better information. I would like to use the Lenmartz method with my Ranger, so I am = interested in=20 your future progress. Jack=20 ________________________________________ From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Andreas Tschammer Sent: Friday, November 30, 2007 4:13 AM To: PSN-L@.............. Subject: HS-10-1 questions Hi all, =A0 my name is Andreas Tschammer and I am from Germany. I recently bought a Geospace HS-10-1 vertical sensor (400 Ohms 3 V/ips) at ebay from=20 a German surplus dealer. I would like to do some experiments with active damping/period extension (Lennartz-Method) = http://www.lennartz-electronic.de/ and=A0 http://www.terrajp.co.jp/Seismometers.pdf=A0 (pp. 50). =A0 Today I found the time to do some tests to help me to decide whether=20 to keep it or to send it back. It was not really a bargain, so it should = work 100%. I was using a resistive bridge - as described by ST Morrissey - to check the resonance frequency and linearity. I removed the 2k2 resistor from = the terminals of the phone. The resonance was not very pronounced=A0 between 1 Hz and 2 Hz. The sine current from the function generator was about = 30-100 uA peak-peak. The up/down movement of the period adjustment screw was very = small but visible. Especially below 1 Hz the output voltage of the coil was non sinusoidal. = It looked as if=20 the mass got stuck by some kind of friction and then was released as the = current was growing. I could make a picture of the oscilloskope screen if this helps. I have a 24 Hz geophone which=A0has always a linear/sinusoidal = output=A0during this test.=20 The resonance=A0is also clearly visible.=20 I am afraid the nonlinearity=A0of the HS-10 will be a problem when I try = to LP filter the signal by software to get rid of the high frequency seismic noise. The HS-10 seems to be pretty sensitive. I have it sitting on the ground = of the basement of my house with a x100 amplifier and digital oscilloscope connected. I can see = movements all the time. It gets lower at night (15 mVpp)=A0but still a lot of avtivity althought no cars = can be heard outside. So its not totally dead. The coil resistance is ok. I can hear some kind of klicking noise when I = move the mass by the=A0period adjustment=20 rod slowly up and down. I am not sure whether it comes from the = astitisizing (typo?)=A0spring or from the inside of the housing. =A0 Do you know whether this kind of non linear behaviour of the HS-10 is = normal?=20 Can you recommend any other test that can be done with normal electronic = lab=20 equipment to check the HS-10?=20 Is it possible/recommended to open the housing? I was not able to find a = way to open it. Maybe I can see the problem inside..=20 =A0 I really would like to keep the HS-10, so any kind of advise is welcome. Thank you very much in advance for your help! =A0 Andreas Tschammer Rheinbach, Germany __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: "Andreas Tschammer" asensio@............ Date: Fri, 30 Nov 2007 22:02:57 +0100 @ Jón / Jack, the clicking noise is barely audible and is not the from the mass hitting the mechnical stop. The noise forms when I move the mass slowly by hand with the period adjustment rod. It sounds like a noise from a spring but I can not tell whether it comes from the period adjustment spring outside of the housing or from the main leafspring inside. Maybe the noise comes from the cause of the unlinearity... My HS-10 has a locking screw for the mass for transportation. There is no real centering indicator on my HS-10 but there is a threaded rod that comes from the inside and is connected to the mass. There is a spring outside of the housing whose force can be adjusted by a bushing on the rod. The mass can move 6 mm up and 6 mm down. The rest position of the mass is roughly in the center of the movement range of the mass, so the centering should be ok. When I reduce the drive current to 10 uA the seismic noise is too high to evaluate the form of the curve on the oscilloscope. I will try to build a simple filter to reduce the high frequency seismic noise and check the response with lower drive current at low frequencies. With about 30 uApp the movement of the adjustment screw/rod is about 1 mm. I think the response should still be linear at a 1 mm movement but the output voltage looks more like a triangle. Maybe I demand too much ... Andreas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: ChrisAtUpw@....... Date: Fri, 30 Nov 2007 17:10:53 EST In a message dated 30/11/2007 21:03:24 GMT Standard Time, asensio@............ writes: With about 30 uApp the movement of the adjustment screw/rod is about 1 mm. I think the response should still be linear at a 1 mm movement but the output voltage looks more like a triangle. Maybe I demand too much ... Hi Andreas, I suggest treating your HS-10 with considerable care. You might read through old letters by Sean Morrissey on psn. I remember him replacing springs regularly. Now you only want the sensor to move microns, so I suggest that you connect it to the input of a current to voltage converter opamp and then use a 1/f amplifier stage to roll off the signal. This should give you a good idea of what performance you can expect. Going from 3 K to 400 Ohms will greatly overdamp it. Later, you might use a negative input impedance amplifier to give ~zero impedance, but you need to provide a temperature compensated reference resistor. This could be as simple as a Ni thermometer element and a resistor, or a non inductively wound coil of copper wire - if you can get it thin enough. Pt has a slightly lower temperature coefficient. 0 to 100 C for Cu = 1.44, Pt = 1.32, Ni = 1.70. Could you send an EMail to the manufacturer? They should be able to advise you. Regards, Chris Chapman
In a message dated 30/11/2007 21:03:24 GMT Standard Time,=20 asensio@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>With=20 about 30 uApp the movement of the adjustment screw/rod is about 1 mm.
I= =20 think the response should still be linear at a 1 mm movement but
the ou= tput=20 voltage looks more like a triangle. Maybe I demand too much=20 ....
Hi Andreas,
 
    I suggest treating your HS-10 with considerable= =20 care. You might read through old letters by Sean Morrissey on psn. I remembe= r=20 him replacing springs regularly.
    Now you only want the sensor to move microns, s= o I=20 suggest that you connect it to the input of a current to voltage=20 converter opamp and then use a 1/f amplifier stage to roll off the sign= al.=20 This should give you a good idea of what performance you can expect. Going f= rom=20 3 K to 400 Ohms will greatly overdamp it.  Later, you might use a negat= ive=20 input impedance amplifier to give ~zero impedance, but you need to provide a= =20 temperature compensated reference resistor. This could be as simple as a Ni=20 thermometer element and a resistor, or a non inductively wound coil of coppe= r=20 wire - if you can get it thin enough. Pt has a slightly lower temperatu= re=20 coefficient. 0 to 100 C  for Cu =3D 1.44, Pt =3D 1.32, Ni =3D 1.70= ..
    Could you send an EMail to the manufacturer? Th= ey=20 should be able to advise you.
 
    Regards,
 
    Chris Chapman
Subject: Re: Mw7.3 earthquake From: "Geoff" gmvoeth@........... Date: Fri, 30 Nov 2007 22:46:23 -0700 Howdy Pardners; I saw this one come in too and because there seemed to be high freq components to the signal I( mistankened it for a smaller regional quake. Then I heard on the TV news that it was mistaken by the big boys as a california quake so I did not feel too bad about misguessing it. ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Thursday, November 29, 2007 1:02 PM Subject: Mw7.3 earthquake Hi all At 19:00 GMT tonight there was a Mw7.3 earthquake ( preliminary size) near Leeward Islands. According to EMSC the depth of the earthquake was 153km. So far I don't have heard any news about this earthquake in internatonal news. But I do expect to see news in one or two hours about it. If there was any damage in this earthquake. Here is the EMSC link. http://www.emsc-csem.org/index.php?page=current&sub=detail&id=71249 This earthquake was picked up by two of my stations. Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mw7.3 earthquake From: "Geoff" gmvoeth@........... Date: Fri, 30 Nov 2007 22:46:23 -0700 Howdy Pardners; I saw this one come in too and because there seemed to be high freq components to the signal I( mistankened it for a smaller regional quake. Then I heard on the TV news that it was mistaken by the big boys as a california quake so I did not feel too bad about misguessing it. ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Thursday, November 29, 2007 1:02 PM Subject: Mw7.3 earthquake Hi all At 19:00 GMT tonight there was a Mw7.3 earthquake ( preliminary size) near Leeward Islands. According to EMSC the depth of the earthquake was 153km. So far I don't have heard any news about this earthquake in internatonal news. But I do expect to see news in one or two hours about it. If there was any damage in this earthquake. Here is the EMSC link. http://www.emsc-csem.org/index.php?page=current&sub=detail&id=71249 This earthquake was picked up by two of my stations. Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: "Geoff" gmvoeth@........... Date: Fri, 30 Nov 2007 22:49:27 -0700 If you purchased the HS10 new ($2500 USD) then the MFG is the right place to go but if you got it used ($250USD)they want nothing to do with you. ----- Original Message ----- From: To: Sent: Friday, November 30, 2007 3:10 PM Subject: Re: HS-10-1 questions > > In a message dated 30/11/2007 21:03:24 GMT Standard Time, > asensio@............ writes: > > With about 30 uApp the movement of the adjustment screw/rod is about 1 mm. > I think the response should still be linear at a 1 mm movement but > the output voltage looks more like a triangle. Maybe I demand too much ... > > > > Hi Andreas, > > I suggest treating your HS-10 with considerable care. You might read > through old letters by Sean Morrissey on psn. I remember him replacing springs > regularly. > Now you only want the sensor to move microns, so I suggest that you > connect it to the input of a current to voltage converter opamp and then use a > 1/f amplifier stage to roll off the signal. This should give you a good idea of > what performance you can expect. Going from 3 K to 400 Ohms will greatly > overdamp it. Later, you might use a negative input impedance amplifier to give > ~zero impedance, but you need to provide a temperature compensated reference > resistor. This could be as simple as a Ni thermometer element and a resistor, > or a non inductively wound coil of copper wire - if you can get it thin > enough. Pt has a slightly lower temperature coefficient. 0 to 100 C for Cu = > 1.44, Pt = 1.32, Ni = 1.70. > Could you send an EMail to the manufacturer? They should be able to > advise you. > > Regards, > > Chris Chapman > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: "Geoff" gmvoeth@........... Date: Fri, 30 Nov 2007 23:16:23 -0700 If your amplifier was designed for a 24 Hz geophone it may not function right for a 1Hz If you give your HS1 a gain of 1000 with a straight through opamp into a 8 or 9 bit converter you should be able to ping it with a 1mv to 100 uv across the leads and get a nice sine wave if you use a diff amp with high input impedance. I recommend you equalize it to 4seconds to 2 Hz or possibly 1Hz to 2 Hz like the TUC station for noisy background areas or wide open up to 10Hz if you are in a quiet area. I think you are not doing the opamp side of things if not then you need the properly designed amp from the pros. I too have an HS10-1 at 1Hz and am getting a acceptable picture for a total amature layman this device is 400 Ohms very cold and about 440 Ohms in the summer. That was b4 I put it underground maybe 24 inches. 24 inches deep being the base. A diff amp you must match the components as closely as possible for best CMMR ( Common mode rejection ) and any temp changes only affect the gain and not the baseline if you zero it correctly. Or so it seems to me. Diff amp is where you hang the input to the op amp +/- leads through two matched resistors like 4700 ohms if you want to damp more you put two matched resistors to ground right at the geophone input. For a 400 ohm unit 2K total damping seems to work OK. The feedback resistors must also be matched and a Two capacitors are needed across eack either at about 10 Hz for a flat response DC to 10Hz or at 4 seconds if you want things somewhat flat between 4 seconds and 2 Hz. 470K feedbacks seem to work well Please be very careful with the preamp design it will set the pace for everything that follows. I have only found two designs for the preamp that worked for me using op177G op amps. That were last MFG in the Philippines. Just for fun: I was waiting for a flight to catch my ship in the tonkin gulf in 1972 when at the air terminal I was ripped off by a Hari Krishna nut looking for money for the Youth In Asia Movement when I realized why these strange people will sit in a lotus position and chant the word "OOhhhmmm" If you had 1,000,000 people doing this you'd have a mega"OOhhhmmm"s of resistance :-) For 5 USD I got this strange book that had a god with 6 arms or more and since then at many times Id like to have such a deformity. Merry Hari Krishna, Hari Rama to everyone. Regards; Geoff ----- Original Message ----- From: "Andreas Tschammer" To: Sent: Friday, November 30, 2007 2:12 AM Subject: HS-10-1 questions Hi all, my name is Andreas Tschammer and I am from Germany. I recently bought a Geospace HS-10-1 vertical sensor (400 Ohms 3 V/ips) at ebay from a German surplus dealer. I would like to do some experiments with active damping/period extension (Lennartz-Method) http://www.lennartz-electronic.de/ and http://www.terrajp.co.jp/Seismometers.pdf (pp. 50). Today I found the time to do some tests to help me to decide whether to keep it or to send it back. It was not really a bargain, so it should work 100%. I was using a resistive bridge - as described by ST Morrissey - to check the resonance frequency and linearity. I removed the 2k2 resistor from the terminals of the phone. The resonance was not very pronounced between 1 Hz and 2 Hz. The sine current from the function generator was about 30-100 uA peak-peak. The up/down movement of the period adjustment screw was very small but visible. Especially below 1 Hz the output voltage of the coil was non sinusoidal. It looked as if the mass got stuck by some kind of friction and then was released as the current was growing. I could make a picture of the oscilloskope screen if this helps. I have a 24 Hz geophone which has always a linear/sinusoidal output during this test. The resonance is also clearly visible. I am afraid the nonlinearity of the HS-10 will be a problem when I try to LP filter the signal by software to get rid of the high frequency seismic noise. The HS-10 seems to be pretty sensitive. I have it sitting on the ground of the basement of my house with a x100 amplifier and digital oscilloscope connected. I can see movements all the time. It gets lower at night (15 mVpp) but still a lot of avtivity althought no cars can be heard outside. So its not totally dead. The coil resistance is ok. I can hear some kind of klicking noise when I move the mass by the period adjustment rod slowly up and down. I am not sure whether it comes from the astitisizing (typo?) spring or from the inside of the housing. Do you know whether this kind of non linear behaviour of the HS-10 is normal? Can you recommend any other test that can be done with normal electronic lab equipment to check the HS-10? Is it possible/recommended to open the housing? I was not able to find a way to open it. Maybe I can see the problem inside.. I really would like to keep the HS-10, so any kind of advise is welcome. Thank you very much in advance for your help! Andreas Tschammer Rheinbach, Germany __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: "Geoff" gmvoeth@........... Date: Fri, 30 Nov 2007 23:16:23 -0700 If your amplifier was designed for a 24 Hz geophone it may not function right for a 1Hz If you give your HS1 a gain of 1000 with a straight through opamp into a 8 or 9 bit converter you should be able to ping it with a 1mv to 100 uv across the leads and get a nice sine wave if you use a diff amp with high input impedance. I recommend you equalize it to 4seconds to 2 Hz or possibly 1Hz to 2 Hz like the TUC station for noisy background areas or wide open up to 10Hz if you are in a quiet area. I think you are not doing the opamp side of things if not then you need the properly designed amp from the pros. I too have an HS10-1 at 1Hz and am getting a acceptable picture for a total amature layman this device is 400 Ohms very cold and about 440 Ohms in the summer. That was b4 I put it underground maybe 24 inches. 24 inches deep being the base. A diff amp you must match the components as closely as possible for best CMMR ( Common mode rejection ) and any temp changes only affect the gain and not the baseline if you zero it correctly. Or so it seems to me. Diff amp is where you hang the input to the op amp +/- leads through two matched resistors like 4700 ohms if you want to damp more you put two matched resistors to ground right at the geophone input. For a 400 ohm unit 2K total damping seems to work OK. The feedback resistors must also be matched and a Two capacitors are needed across eack either at about 10 Hz for a flat response DC to 10Hz or at 4 seconds if you want things somewhat flat between 4 seconds and 2 Hz. 470K feedbacks seem to work well Please be very careful with the preamp design it will set the pace for everything that follows. I have only found two designs for the preamp that worked for me using op177G op amps. That were last MFG in the Philippines. Just for fun: I was waiting for a flight to catch my ship in the tonkin gulf in 1972 when at the air terminal I was ripped off by a Hari Krishna nut looking for money for the Youth In Asia Movement when I realized why these strange people will sit in a lotus position and chant the word "OOhhhmmm" If you had 1,000,000 people doing this you'd have a mega"OOhhhmmm"s of resistance :-) For 5 USD I got this strange book that had a god with 6 arms or more and since then at many times Id like to have such a deformity. Merry Hari Krishna, Hari Rama to everyone. Regards; Geoff ----- Original Message ----- From: "Andreas Tschammer" To: Sent: Friday, November 30, 2007 2:12 AM Subject: HS-10-1 questions Hi all, my name is Andreas Tschammer and I am from Germany. I recently bought a Geospace HS-10-1 vertical sensor (400 Ohms 3 V/ips) at ebay from a German surplus dealer. I would like to do some experiments with active damping/period extension (Lennartz-Method) http://www.lennartz-electronic.de/ and http://www.terrajp.co.jp/Seismometers.pdf (pp. 50). Today I found the time to do some tests to help me to decide whether to keep it or to send it back. It was not really a bargain, so it should work 100%. I was using a resistive bridge - as described by ST Morrissey - to check the resonance frequency and linearity. I removed the 2k2 resistor from the terminals of the phone. The resonance was not very pronounced between 1 Hz and 2 Hz. The sine current from the function generator was about 30-100 uA peak-peak. The up/down movement of the period adjustment screw was very small but visible. Especially below 1 Hz the output voltage of the coil was non sinusoidal. It looked as if the mass got stuck by some kind of friction and then was released as the current was growing. I could make a picture of the oscilloskope screen if this helps. I have a 24 Hz geophone which has always a linear/sinusoidal output during this test. The resonance is also clearly visible. I am afraid the nonlinearity of the HS-10 will be a problem when I try to LP filter the signal by software to get rid of the high frequency seismic noise. The HS-10 seems to be pretty sensitive. I have it sitting on the ground of the basement of my house with a x100 amplifier and digital oscilloscope connected. I can see movements all the time. It gets lower at night (15 mVpp) but still a lot of avtivity althought no cars can be heard outside. So its not totally dead. The coil resistance is ok. I can hear some kind of klicking noise when I move the mass by the period adjustment rod slowly up and down. I am not sure whether it comes from the astitisizing (typo?) spring or from the inside of the housing. Do you know whether this kind of non linear behaviour of the HS-10 is normal? Can you recommend any other test that can be done with normal electronic lab equipment to check the HS-10? Is it possible/recommended to open the housing? I was not able to find a way to open it. Maybe I can see the problem inside.. I really would like to keep the HS-10, so any kind of advise is welcome. Thank you very much in advance for your help! Andreas Tschammer Rheinbach, Germany __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re: HS-10-1 questions From: "Andreas Tschammer" psn@............ Date: Sat, 1 Dec 2007 14:53:49 +0100 Jack, I am very interested in a manual scan of the HS-10! Please send it to: psn(at)datelsoft.de Thanks a lot! I also suspect someone mistreated my HS-10 some time ago... Great news you want to do the test on your Ranger! I will redo the test today because I was in a hurry last time. The test was described here: http://www.seismicnet.com/psnlist/991005_204504_1.html I wanted to check the resonance frequency when I saw the distortions of the output voltage. They were worst below 1 Hz. I am using now a Burr Brown PGA204 instrumentation amp for my tests. Later I want to try a LT1028/1128. Does anyone know a better amp for a 400 Ohms coil? I also will try to reacitivate a AD-board I built some time ago with the ADS1211 on it. Maybe I will try to contact Geospace one more time. The last time I asked for more detailed data on the HS-10 I didn´t get an answer. Only one year ago as I asked for a quote I got one.... Time is money, isn´t it? Andreas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: ChrisAtUpw@....... Date: Sat, 1 Dec 2007 10:30:57 EST In a message dated 01/12/2007, psn@............ writes: I am using now a Burr Brown PGA204 instrumentation amp for my tests. Later I want to try a LT1028/1128. Does anyone know a better amp for a 400 Ohms coil? Hi Andreas, The PGA 204 is relatively noisy The LT1028 is a bit better than the LT1007CN8, but more expensive. You need to design the -ve input circuit with maybe 200 Ohms max to ground and the geophone onto the +ve input. You can get lower noise if you use a differential input pair of low noise transistors onto a LM301 opamp or similar. Regards, Chris Chapman
In a message dated 01/12/2007, psn@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am=20 using now a Burr Brown PGA204 instrumentation amp  for my tests.=20 Later
I want to try a
LT1028/1128. Does anyone know a better amp for= a=20 400 Ohms coil?
Hi Andreas,
 
    The PGA 204 is relatively noisy
 
    The LT1028 is a bit better than the LT1007CN8,=20= but=20 more expensive. You need to design the -ve input circuit with maybe 200 Ohms= max=20 to ground and the geophone onto the +ve input.
 
    You can get lower noise if you use a differenti= al=20 input pair of low noise transistors onto a LM301 opamp or similar.
 
    Regards,
 
    Chris Chapman 
Subject: Re: HS-10-1 questions From: "Andreas Tschammer" psn@............ Date: Sat, 1 Dec 2007 22:11:41 +0100 I received the manuals. Thank you Jack! I did the test with the resistive bridge again with and without damping resistor attached. I was not able to confirm the resonance at 1 Hz (but one at abt. 24 Hz). There was always a nonsinusoidal response to a sine current into the main coil. This alone is not good I would say.. I also injected a sine current (40 uApp, 0.5 Hz) via a 100k resistor into the main coil and watched the resulting sum signal with an amplification of 100 on the scope. One should expect a sinosoidal signal since any superposition of two sines results in a sine, but it looked very similar to the signal from the bridge. The movement of the mass was max. +/- 0.1 mm and barely visible. Here the scope screen of the injected current (sine curve) and the sum of the current into the resistance of the coil plus the induced voltage from the moving coil: http://www.datelsoft.de/PSN/curr_HS-10.jpg I also turned the period vernier from its lower to upper limit in 1/4 turns. There were jumps in amplitude during this. I would expect a steady change in ampltiude while turning the vernier. Andreas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10-1 questions From: "Geoff" gmvoeth@........... Date: Sun, 2 Dec 2007 04:13:49 -0700 Can You Please Show us how the two transistors are used along with the opamp in some kind of GIF Image schematic ?? ----- Original Message ----- From: To: Sent: Saturday, December 01, 2007 8:30 AM Subject: Re: HS-10-1 questions > > In a message dated 01/12/2007, psn@............ writes: > > I am using now a Burr Brown PGA204 instrumentation amp for my tests. Later > I want to try a > LT1028/1128. Does anyone know a better amp for a 400 Ohms coil? > > > > Hi Andreas, > > The PGA 204 is relatively noisy > > The LT1028 is a bit better than the LT1007CN8, but more expensive. You > need to design the -ve input circuit with maybe 200 Ohms max to ground and the > geophone onto the +ve input. > > You can get lower noise if you use a differential input pair of low > noise transistors onto a LM301 opamp or similar. > > Regards, > > Chris Chapman > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10 manual From: "Andreas Tschammer" psn@............ Date: Sun, 2 Dec 2007 23:05:13 +0100 Jack, thank you very much for doing this test! Your findings confirm my decision to (try) to return it to the dealer. He is on holidays now, so communication is somewhat slow. He has a second HS-10, maybe he will test this one with the simpler 100 k resistor test for linearity. But I expect a similar result.. Maybe I should reactivate my VBB project instead. I tried to reproduce a very compact VBB design (inv. pendulum) from a scientific journal with a small mass (~50g) and blumelein bridge capacitive displacement sensor. It worked quite well for the small size. I could see the 6s microseisms clearly and a ~6 quake in Papua NG. But I had some mass drift problems and lost my interest in it. Andreas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: The way it used to be in the USA From: "Dewayne" n0ssy@........... Date: Sun, 2 Dec 2007 21:12:43 -0700 I just read this and it makes me fell good that there are still SOME = companies that realize their employees make their company what it is. You can bet your sweet ass I'll be doing all my Christmas shopping at = Sears.=20 Dewayne _________________________________________________________________________= ________________________________________ I know I needed this reminder since Sears isn't always my first choice. = Amazing when you think of how long the war has lasted and they haven't = withdrawn from their commitment. Could we each buy at least one thing at = Sears this year? =20 How does Sears treat its employees who are called up for military duty? = By law, they are required to hold their jobs open and available, but = nothing more. Usually, people take a big pay cut and lose benefits as a = result of being called up. =20 Sears is voluntarily paying the difference in salaries and maintaining = all benefits, including medical insurance and bonus programs, for all = called up reservist employees for up to two years.=20 I submit that Sears is an exemplary corporate citizen and should be = recognized for its contribution. I suggest we all shop at Sears, and be = sure to find a manager to tell them why we are there so the company gets = the positive reinforcement it well deserves. =20 Pass it on. =20 Decided to check this before I sent it forward. So I sent the following = email to the Sears Customer Service Department: =20 I received this e-mail and I would like to know if it is true. If it is, = the Internet may have just become one very good source of advertisement = for your company. I know I would go out of my way to buy products from = Sears instead of another store for a like item, even if it's cheaper at = that store. =20 This is Sears answer to my e-mail: =20 Dear Customer: =20 Thank you for contacting Sears.The information is factual. We appreciate = your positive feedback. =20 Sears regards service to our country as one of greatest sacrifices our = young men and women can make. We are happy to do our part to lessen the = burden they bear at this time. =20 Bill Thorn =20 Sears Customer Care =20 webcenter@......... =20 1-800- 349-4358=20 Please pass this on to all your friends. Sears needs to be recognized = for this outstanding contribution and we need to show them as Americans, = we do appreciate what they are doing for our military.
I just read this and it makes me fell = good that=20 there are still SOME companies that realize = their employees make=20 their company what it is.
 
You can bet your sweet ass I'll = be doing=20 all my Christmas shopping at Sears. 
 
Dewayne
 
 
________________________________________________________________= _________________________________________________
 
I know I needed this reminder since Sears isn't = always my=20 first choice. Amazing when you think of how long the war has lasted and = they=20 haven't withdrawn from their commitment. Could we each buy at least one = thing at=20 Sears this year? =20
How does Sears treat its employees who are called up = for=20 military duty? By law, they are required to hold their jobs open and = available,=20 but nothing more. Usually, people take a big pay cut and lose benefits = as a=20 result of being called up. =20
Sears is voluntarily paying the difference in = salaries and=20 maintaining all benefits, including medical insurance and bonus = programs, for=20 all called up reservist employees for up to two years.=20
I submit that Sears is an exemplary corporate = citizen and=20 should be recognized for its contribution. I suggest we all shop at = Sears, and=20 be sure to find a manager to tell them why we are there so the company = gets the=20 positive reinforcement it well deserves. =20
Pass it on. =20
Decided to check this before I sent it forward. So I = sent the=20 following email to the Sears Customer Service Department: =20
I received this e-mail and I would like to know if = it is true.=20 If it is, the Internet may have just become one very good source of=20 advertisement for your company. I know I would go out of my way to buy = products=20 from Sears instead of another store for a like item, even if it's = cheaper at=20 that store. =20
This is Sears answer to my e-mail: =20
Dear Customer: =20
Thank you for contacting Sears.The information is = factual. We=20 appreciate your positive feedback. =20
Sears regards service to our country as one of = greatest=20 sacrifices our young men and women can make. We are happy to do our part = to=20 lessen the burden they bear at this time. =20
Bill Thorn =20
Sears Customer Care =20
<mailto:webcenter@.........>webcenter@............  =20
1-800- 349-4358=20
Please pass this on to all your friends. Sears needs = to be=20 recognized for this outstanding contribution and we need to show them as = Americans, we do appreciate what they are doing for our = military. =20
Subject: Re: The way it used to be in the USA From: ChrisAtUpw@....... Date: Sun, 2 Dec 2007 23:20:03 EST In a message dated 03/12/2007 04:15:04 GMT Standard Time, n0ssy@........... writes: I'll be doing all my Christmas shopping at Sears. Hi Dewayne, You might find out when they are going to start selling seismometers? Regards, Chris
In a message dated 03/12/2007 04:15:04 GMT Standard Time, n0ssy@comcast= ..net=20 writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I'll be doing all my Christmas shopping at=20 Sears. 
Hi Dewayne,
 
    You might find out when they are going to start= =20 selling seismometers?
 
    Regards,
 
    Chris
Subject: Re: HS-10 manual From: Brett Nordgren Brett3mr@............. Date: Mon, 03 Dec 2007 10:51:00 -0500 Andreas, Sorry to hear about your HS-10 problem. However, I was also interested in your VBB project. Had you ever considered using a feedback system to stabilize the mass position? It's not a trivial undertaking, but once working, it might help a lot. Where can I see a description of the Blumelein Bridge? Capacitive sensors have always seemed like a good approach to me, and I'm interested in learning about as many designs as I can. Good luck with your project. Brett At 11:05 PM 12/2/2007 +0100, you wrote: >Jack, > >thank you very much for doing this test! Your findings confirm my decision >to (try) to return >it to the dealer. He is on holidays now, so communication is somewhat slow. >He has a second HS-10, maybe he will test this one with the simpler 100 k >resistor test for >linearity. But I expect a similar result.. >Maybe I should reactivate my VBB project instead. I tried to reproduce a >very compact >VBB design (inv. pendulum) from a scientific journal with a small mass >(~50g) and blumelein bridge capacitive >displacement sensor. It worked quite well for the small size. I could see >the 6s microseisms clearly and >a ~6 quake in Papua NG. But I had some mass drift problems and lost my >interest in it. > >Andreas My e-mail address above should be working, but if not you can always use my mail form at: http://bnordgren.org/contactB.html using your Web browser. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: HS-10 manual From: ChrisAtUpw@....... Date: Mon, 3 Dec 2007 11:41:50 EST In a message dated 03/12/2007, Brett3mr@............. writes: Where can I see a description of the Blumelein Bridge? Hi Brett, A Blumlein Bridge might be a centre tapped drive coil connected to a three plate capacitor with the common centre plate voltage compared to the centre tap on the coil. Regards, Chris Chapman
In a message dated 03/12/2007, Brett3mr@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Where=20 can I see a description of the Blumelein Bridge?
 
Hi Brett,
 
    A Blumlein Bridge might be a centre tapped driv= e=20 coil connected to a three plate capacitor with the common centre plate volta= ge=20 compared to the centre tap on the coil.
 
    Regards,
 
    Chris Chapman
Subject: How much gain? From: tchannel1@............ Date: Mon, 3 Dec 2007 17:37:54 -0700 Hi Folks, I am using Larry's board, AmaSeis and Winquake. I just = made a new coil and magnet assembly, using 4000 turns of 38 ga. and a = stack of three ring magnets, each .250 x.750" This replace a coil of 2000 turns and two magnets .250 x.750" Larry's = board in set for the high gain, but with the pot turn all the way down = to minimum. My question is what is the best approach to setting the Amp. gain? = This new coil arrangement is more powerful the the last one. Using = AmaSeis the helicorder gain in 1 or 2, more than that is too much. I = know this gain adjustment is just for viewing, and 1 or 2 looks okay. I could move the jumper on Larry's board to the lower gain level, or I = could leave it on the higher gain. I am just looking for some advise as to setting the gain. =20 The best one I heard, was to use a quiet night and set the gain to show = none or just a little back ground noise. Thanks, Ted
Hi Folks,   I am using = Larry's board,=20 AmaSeis and Winquake.   I just made a new coil and magnet = assembly,=20 using 4000 turns of 38 ga. and a stack of three ring magnets, each .250=20 x.750"
This replace a coil of 2000 turns and = two magnets=20 ..250 x.750"   Larry's board in set for the high gain, but with = the pot=20 turn all the way down to minimum.
 
My question is what is the best = approach to setting=20 the Amp. gain?   This new coil arrangement is more powerful = the the=20 last one.  Using AmaSeis the helicorder gain in 1 or 2, more than = that is=20 too much.   I know this gain adjustment is just for viewing, = and 1 or=20 2 looks okay.
 
I could move the jumper on Larry's = board to the=20 lower gain level, or I could leave it on the higher gain.
 
I am just looking for some advise as to = setting the=20 gain. 
The best one I heard, was to use a = quiet night and=20 set the gain to show none or just a little back ground = noise.
 
Thanks, Ted
Subject: Re: How much gain? From: ChrisAtUpw@....... Date: Mon, 3 Dec 2007 21:45:47 EST In a message dated 04/12/2007, tchannel1@............ writes: I am using Larry's board, AmaSeis and Winquake. I just made a new coil and magnet assembly, using 4000 turns of 38 ga. and a stack of three ring magnets, each .250 x.750" This replace a coil of 2000 turns and two magnets .250 x.750" Larry's board in set for the high gain, but with the pot turn all the way down to minimum. My question is what is the best approach to setting the Amp. gain? This new coil arrangement is more powerful the the last one. Using AmaSeis the helicorder gain in 1 or 2, more than that is too much. I know this gain adjustment is just for viewing, and 1 or 2 looks okay. I could move the jumper on Larry's board to the lower gain level, or I could leave it on the higher gain. I am just looking for some advise as to setting the gain. The best one I heard, was to use a quiet night and set the gain to show none or just a little back ground noise. Hi Ted, First, check the gain and measure the noise when the magnet is away from the sensor. Then turn the gain up to maximum and check again. Use the 'Show Data Values' in AmaSeis. It can be informative to record the trace for an hour or more to see if you are getting any noise pickup. The two essential factors that you DON'T mention are the period of the sensor and the resolution of your ADC! Assuming that you are using a 12 bit ADC and that you can sense the 6 second microseisms, you want to be able to actually measure seismic signals of less than 1/20 the average 2 micron displacement - minimum ~0.5 micron. Set the gain initially to give a background of at least +/-20 total counts, then look at the short period and long period filtered counts. Increase the gain to give at least +/-10 filtered counts in the seismic periods of interest. Then start recording quakes and see whether your gain setting a) records small quakes OK and b) doesn't saturate the trace on most of the large quakes. If you can sense out to 20 seconds, you can run the low pass display filter at 8 to 10 seconds and pick out the surface waves. You can then use filters to hunt for the P and S waves if they are not obvious on the raw extracted trace. There is a long period display filter in AmaSeis to compensate for sort periods, but it does need some counts to do the arithmetic! Regards, Chris Chapman
In a message dated 04/12/2007, tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I am using Larry's board, AmaSeis and=20 Winquake.   I just made a new coil and magnet assembly, using 40= 00=20 turns of 38 ga. and a stack of three ring magnets, each .250=20 x.750"
This replace a coil of 2000 turns and two= magnets=20 .250 x.750"   Larry's board in set for the high gain, but with t= he=20 pot turn all the way down to minimum.
 
My question is what is the best approach=20= to=20 setting the Amp. gain?   This new coil arrangement is more power= ful=20 the the last one.  Using AmaSeis the helicorder gain in 1 or 2, more=20= than=20 that is too much.   I know this gain adjustment is just for view= ing,=20 and 1 or 2 looks okay.
 
I could move the jumper on Larry's board=20= to the=20 lower gain level, or I could leave it on the higher gain.
 
I am just looking for some advise as to s= etting=20 the gain. 
The best one I heard, was to use a quiet=20= night=20 and set the gain to show none or just a little back ground=20 noise.
Hi Ted,
 
    First, check the gain and measure the noise whe= n=20 the magnet is away from the sensor. Then turn the gain up to maximum and che= ck=20 again. Use the 'Show Data Values' in AmaSeis. It can be informative to recor= d=20 the trace for an hour or more to see if you are getting any noise=20 pickup.
 
    The two essential factors that you DON'T mentio= n=20 are the period of the sensor and the resolution of your ADC! Assuming that y= ou=20 are using a 12 bit ADC and that you can sense the 6 second microseisms, you=20= want=20 to be able to actually measure seismic signals of less than 1/20 the=20 average 2 micron displacement - minimum ~0.5 micron. 
    Set the gain initially to give a backgroun= d of=20 at least +/-20 total counts, then look at the short period and long period=20 filtered counts. Increase the gain to give at least +/-10 filtered counts in= the=20 seismic periods of interest.
    Then start recording quakes and see whether you= r=20 gain setting a) records small quakes OK and b) doesn't saturate the tra= ce=20 on most of the large quakes.
    If you can sense out to 20 seconds, you can run= the=20 low pass display filter at 8 to 10 seconds and pick out the surface wav= es.=20 You can then use filters to hunt for the P and S waves if they are not=20 obvious on the raw extracted trace. There is a long period display filt= er=20 in AmaSeis to compensate for sort periods, but it does need some counts to d= o=20 the arithmetic!
    
    Regards,
 
    Chris Chapman
Subject: Re:How much gain From: Roger Sparks rsparks@.......... Date: Tue, 04 Dec 2007 05:33:55 -0800 In a message dated 04/12/2007, tchannel1@............ writes: "I am using Larry's board, AmaSeis and Winquake. I just made a new coil and magnet assembly, .............. I am just looking for some advise as to setting the gain. The best one I heard, was to use a quiet night and set the gain to show none or just a little back ground noise." Hi Ted, The investigator has two challenges here. The first is the detect every ground motion, however small. This requires the highest possible gain from the initial amplifier. This is comparable to setting the RF (initial) gain in a radio receiver. The second challenge is to display the trace in a pleasing manner. This requires control of the the display gain, and is comparable to setting the audio gain in a radio receiver. Can you get too much gain? Yes, the background noise can overdrive some component into a "clipped" mode, or saturate the display. What is "background noise"? The first background noise is from the electronics. There is no such thing as a perfect amplifier, they all have some minimum noise level. Investigate this noise level by locking your seismometer beam and observe the readings from the A/D device. The second background noise level is from the microsceims caused by ocean waves(?). Atmospherics, human activity and machines can also cause background noise but you will soon learn to recognize these sources. At my station, I often have the background noise from ocean sources reading 100 counts with peaks to 300 or more. Here in Washington State, we have local quakes at frequencies up to 10 hz and more. I can only detect to 5 hz right now (due to sample rate) but I often see traces from the local quakes "riding" on the much slower undulating trace from the ocean waves. Any weak readings from more distance quakes also "ride" on the ocean wave trace. Best wishes, Roger __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re:How much gain From: Roger Sparks rsparks@.......... Date: Tue, 04 Dec 2007 08:39:53 -0800 Ted, In my earlier posting, I forgot to mention noise from the seismometer itself. Every moving contact point will generate friction and noise. Friction is noise. Low friction is low noise. Severe seismometer noise is observed as a "spikey" trace, rather than the smooth wave form that should be seen as a result of the ocean noise. Less severe seismometer noise will appear as small spikes on an undulating ocean wave, but a smooth ocean wave trace can never be observed. On my vertical seismometer, I have eliminated seismometer friction noise by using long springs as the hinge. I still have seismometer noise that could be called "phase" noise that is a result of seismometer damping and motion characteristics. Sorry to have omitted this noise source from my previous posting. Roger __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Wed, 5 Dec 2007 15:39:43 -0700 Hi all, I've put up another "table top test" web page in regard to diamagnetic levitaion of pyrolytic graphite as it could be used in a tiltmeter. The basic design used "old" techniques; but the results seem to be very encouraging thus far, and I felt it would be worthwhile to web page "update" what I have seen or think. The single web page does not cover every aspect involved...that would entail alot more pages I'am sure. See: http://diamagnetics.googlepages.com/home Take care, Meredith Lamb
Hi all,
 
I've put up another "table top test" web page in regard to diamagnetic levitaion of pyrolytic
graphite as it could be used in a tiltmeter.
 
The basic design used "old" techniques; but the results seem to be very encouraging
thus far, and I felt it would be worthwhile to web page "update" what I have seen or think.
The single web page does not cover every aspect involved...that would entail alot more
pages I'am sure.
 
See:
 
 
Take care, Meredith Lamb
 
 
Subject: Re: General Diamagnetic Tiltmeter Improvements From: ChrisAtUpw@....... Date: Wed, 5 Dec 2007 18:46:22 EST In a message dated 05/12/2007 22:40:03 GMT Standard Time, paleoartifact@......... writes: I've put up another "table top test" web page in regard to diamagnetic levitaion of pyrolytic graphite as it could be used in a tiltmeter. Hi Meredith, Can you make a rectangular U out of 5 thou or similar Al foil and stick this lengthways on the Graphite strips, maybe one side with a slot for photocells? Then make an inverted U structure out of mild steel, support it centrally on the outside magnet pairs and fit it with a mild steel bolt downwards over the centre of the Al U channel? Screw down the end of the steel bolt until you get about the right damping? The other way of evening out the magnet field is to use thin strips of Iron (galvanised?) to sit on top of the three magnets, maybe with the edges filed off at 45 degrees? Regards, Chris
In a message dated 05/12/2007 22:40:03 GMT Standard Time,=20 paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I've put up another "table top test" web page in regard to diamagneti= c=20 levitaion of pyrolytic
graphite as it could be used in a=20 tiltmeter.
Hi Meredith,
 
    Can you make a rectangular U out of 5 thou or=20 similar Al foil and stick this lengthways on the Graphite strips, maybe one=20= side=20 with a slot for photocells?
    Then make an inverted U structure out of m= ild=20 steel, support it centrally on the outside magnet pairs and fit it=20 with a mild steel bolt downwards over the centre of the Al U=20 channel? Screw down the end of the steel bolt until you get about the r= ight=20 damping?  
    The other way of evening out the magnet field i= s to=20 use thin strips of Iron (galvanised?) to sit on top of the three magnet= s,=20 maybe with the edges filed off at 45 degrees?
 
    Regards,
 
    Chris
Subject: Re: HS-10 manual From: "Ted Rogers" tedr@........... Date: Thu, 6 Dec 2007 14:38:11 +1100 Brett, Check - http://www.allaboutcircuits.com/vol_2/chpt_12/6.html - page 7, It relates to capacitive sensors, I tried this circuit and it worked fine. There is a book called "the Inventor of Stereo" by Robert C. Alexander, published by Focal Press. The book gives an account of the short life (38 years) of Alan Blumlein and most of his 128 patents. Ted ----- Original Message ----- From: "Brett Nordgren" To: Sent: Tuesday, December 04, 2007 2:51 AM Subject: Re: HS-10 manual > Andreas, > > Sorry to hear about your HS-10 problem. > > However, I was also interested in your VBB project. Had you ever > considered using a feedback system to stabilize the mass position? It's > not a trivial undertaking, but once working, it might help a lot. > > Where can I see a description of the Blumelein Bridge? Capacitive sensors > have always seemed like a good approach to me, and I'm interested in > learning about as many designs as I can. > > Good luck with your project. > > Brett > > At 11:05 PM 12/2/2007 +0100, you wrote: >>Jack, >> >>thank you very much for doing this test! Your findings confirm my decision >>to (try) to return >>it to the dealer. He is on holidays now, so communication is somewhat >>slow. >>He has a second HS-10, maybe he will test this one with the simpler 100 k >>resistor test for >>linearity. But I expect a similar result.. >>Maybe I should reactivate my VBB project instead. I tried to reproduce a >>very compact >>VBB design (inv. pendulum) from a scientific journal with a small mass >>(~50g) and blumelein bridge capacitive >>displacement sensor. It worked quite well for the small size. I could see >>the 6s microseisms clearly and >>a ~6 quake in Papua NG. But I had some mass drift problems and lost my >>interest in it. >> >>Andreas > My e-mail address above should be working, but if not > you can always use my mail form at: http://bnordgren.org/contactB.html > using your Web browser. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Combination spring-mag_levitation Anyone Tried This ?? From: "Geoff" gmvoeth@........... Date: Wed, 5 Dec 2007 20:41:46 -0700 Hello PSN Folks; Has anyone ever used a spring to take up most the mass weight then maybe apply an ounce or less levitation magnetically to set with electronics the free period within a geophone. Id think you would pump a current limited signal into the geophone and use some kind of feedback circuit that might set the free period. I am looking only for a free period in the 3 to 4 second range. If you take up the small weight with your hand it seems you can move the hand up and down at whatever period and the system will not oppose what you are doing ?? Comments welcome. Regards geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Wed, 5 Dec 2007 21:46:52 -0700 Hi Chris, Will try to "engineer" some kind of aluminum sleeve; but of course with some weight limitations involved. Will have to see about the dampening route you suggest. As for the steel application, that would also work. I can't remember exactly the thickness of steel that might be best (?); perhaps somewhere around 0.0315" thick; but perhaps just about anything, would be better than nothing. Its possible to "stick" any photocells used to one side or the other of the PG on the magnet/s and/or its aluminum. Take care, Meredith On Dec 5, 2007 4:46 PM, wrote: > In a message dated 05/12/2007 22:40:03 GMT Standard Time, > paleoartifact@......... writes: > > I've put up another "table top test" web page in regard to diamagnetic > levitaion of pyrolytic > graphite as it could be used in a tiltmeter. > > Hi Meredith, > > Can you make a rectangular U out of 5 thou or similar Al foil and > stick this lengthways on the Graphite strips, maybe one side with a slot for > photocells? > Then make an inverted U structure out of mild steel, support it > centrally on the outside magnet pairs and fit it with a mild steel > bolt downwards over the centre of the Al U channel? Screw down the end of > the steel bolt until you get about the right damping? > The other way of evening out the magnet field is to use thin strips of > Iron (galvanised?) to sit on top of the three magnets, maybe with the edges > filed off at 45 degrees? > > Regards, > > Chris >
Hi Chris,
 
Will try to "engineer" some kind of aluminum sleeve; but of course with some weight
limitations involved.
 
Will have to see about the dampening route you suggest.
 
As for the steel application, that would also work.  I can't remember exactly the
thickness of steel that might be best (?); perhaps somewhere around 0.0315" thick;
but perhaps just about anything, would be better than nothing.
 
Its possible to "stick" any photocells used to one side or the other of the PG
on the magnet/s and/or its aluminum.
 
Take care, Meredith 

On Dec 5, 2007 4:46 PM, <ChrisAtUpw@.......> wrote:
In a message dated 05/12/2007 22:40:03 GMT Standard Time, paleoartifact@......... writes:
I've put up another "table top test" web page in regard to diamagnetic levitaion of pyrolytic
graphite as it could be used in a tiltmeter.
Hi Meredith,
 
    Can you make a rectangular U out of 5 thou or similar Al foil and stick this lengthways on the Graphite strips, maybe one side with a slot for photocells?
    Then make an inverted U structure out of mild steel, support it centrally on the outside magnet pairs and fit it with a mild steel bolt downwards over the centre of the Al U channel? Screw down the end of the steel bolt until you get about the right damping?  
    The other way of evening out the magnet field is to use thin strips of Iron (galvanised?) to sit on top of the three magnets, maybe with the edges filed off at 45 degrees?
 
    Regards,
 
    Chris

Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? From: "meredith lamb" paleoartifact@......... Date: Thu, 6 Dec 2007 10:48:06 -0700 Hi Geoff, No, "I" haven't heard of such....however right off I can't think of "how" one would do such especially with only one coil in a geophone. Perhaps "if" you get away from a geophone and wander into say...a simple hanging spring with a mass on the bottom, then it might be more interesting (relatively unknown territory) as you might be able to add stuff, and go from there. My nephew David has used a hanging directional (horizontal) "S-G", with a natural period of ~ 1.5s and "added" acouple magnets; one to the bottom of the mass, and a much larger flat one below that. The magnets are arranged to be repelling; i.e., with the same pole facing each other. If you carefully adjust the larger magnet it will extend the natural period of the S-G somewhat. David claimed he got up to a reliable 8 second natural period; but it involved precisely setting the positions of the magnets. David claims he got up to 11 seconds; but that was alot less stable. He "settled" on using samarium magnets for his model, as the temperature results with neodymium magnets was less suitable. I roughly tried it myself with the table top directional hanging horizontal model I have with the cross rod magnets pivot...about 10 days ago. I only used a box on the floor to put the larger magnet on and position it directly underneath the small magnet on the bottom of the mass.....it was easy to get a extended 3 second period initially. Visually it "appeared" that the undampened free oscillation swinging motion was reasonably harmonic. I suppose there is likely a problem or problems with doing such...I've not really thought about it since the brief trial. If one uses a coil and other magnets on such...then things get hairy with perhaps the potential of magnetic interaction potential problems...especially if the distances between the magnets is too close. How the above could apply to your initial question; in regard to a hanging spring and mass or what results you might see are unknown. I suppose one could also try such with about any vertical just to explore what happens? I would think the magnets "might" have to be, directly in front of the mass for a "traditional" vertical layout; rather than underneath.... I think Sprengnether company initially tried one or more magnetic seismometers way back in time. But I know nothing of their results. Good unknown questions, with no immediate answers....this is the kind of chewy stuff that makes for some fun trials.... Take care, Meredith On Dec 5, 2007 8:41 PM, Geoff wrote: > Hello PSN Folks; > > Has anyone ever used a spring > to take up most the mass weight then > maybe apply an ounce or less levitation > magnetically to set with electronics > the free period within a geophone. > > Id think you would pump a current limited signal > into the geophone and use some kind of > feedback circuit that might set > the free period. I am looking only > for a free period in the 3 to 4 second > range. > > If you take up the small weight with your hand > it seems you can move the hand up and down > at whatever period and the system will > not oppose what you are doing ?? > > Comments welcome. > > Regards > geoff > __________________________________________________________ >
Hi Geoff,
 
No, "I" haven't heard of such....however right off I can't think of "how" one would do such
especially with only one coil in a geophone.  Perhaps "if" you get away from a geophone
and wander into say...a simple hanging spring with a mass on the bottom, then it might
be more interesting (relatively unknown territory) as you might be able to add stuff, and go from there.  
My nephew David has used a hanging directional (horizontal) "S-G", with a natural period of ~ 1.5s
and "added" acouple magnets; one to the bottom of the mass, and a much larger flat one below
that.  The magnets are arranged to be repelling; i.e., with the same pole facing each other.
If you carefully adjust the larger magnet it will extend the natural period of the S-G somewhat.
David claimed he got up to a reliable 8 second natural period; but it involved precisely setting the
positions of the magnets.  David claims he got up to 11 seconds; but that was alot less stable.
He "settled" on using samarium magnets for his model, as the temperature results with
neodymium magnets was less suitable.
 
I roughly tried it myself with the table top directional hanging horizontal model I have with
the cross rod magnets pivot...about 10 days ago.  I only used a box on the floor to put the
larger magnet on and position it directly underneath the small magnet on the bottom of the
mass.....it was easy to get a extended 3 second period initially.  Visually it "appeared" that
the undampened free oscillation swinging motion was reasonably harmonic.  
 
I suppose there is likely a problem or problems with doing such...I've not really thought about
it since the brief trial.  If one uses a coil and other magnets on such...then things get hairy
with perhaps the potential of magnetic interaction potential problems...especially if the 
distances between the magnets is too close. 
 
How the above could apply to your initial question; in regard to a hanging spring and mass
or what results you might see are unknown.   
 
I suppose one could also try such with about any vertical just to explore what happens?
I would think the magnets "might" have to be, directly in front of the mass for a "traditional"
vertical layout; rather than underneath....
 
I think Sprengnether company initially tried one or more magnetic seismometers way back
in time.  But I know nothing of their results.
 
Good unknown questions, with no immediate answers....this is the kind of chewy stuff
that makes for some fun trials.... 
 
Take care, Meredith      
On Dec 5, 2007 8:41 PM, Geoff <gmvoeth@...........> wrote:
Hello PSN Folks;

Has anyone ever used a spring
to take up most the mass weight then
maybe apply an ounce or less levitation
magnetically to set with electronics
the free period within a geophone.

Id think you would pump a current limited signal
into the geophone and use some kind of
feedback circuit that might set
the free period. I am looking only
for a free period in the 3 to 4 second
range.

If you take up the small weight with your hand
it seems you can move the hand up and down
at whatever period and the system will
not oppose what you are doing ??

Comments welcome.

Regards
geoff
__________________________________________________________

Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? From: "meredith lamb" paleoartifact@......... Date: Thu, 6 Dec 2007 11:32:31 -0700 Hi all, This is kind of a "addenum" email. Before I "hear" about it...yes, there is a BIG problem with using a magnetic mass, and of course, THAT, is; its subject to any temporary passing magnetic "noise" source such as a passing car, truck, bus etc. If unshielded....in a real way, it becomes kind of a seismo and a rough weak "magnetometer" combination. About the only "solution" is to encase the magnetic seismometer in a reasonably shielded case; and even then it might be partially "iffy" for some signal noise you see. In the sense of using magnetics as a question to extend the period of a mass....then thats "the" question to explore. Take care, Meredith
Hi all,
 
This is kind of a "addenum" email.
 
Before I "hear" about it...yes, there is a BIG problem with using a magnetic mass, and
of course, THAT, is; its subject to any temporary passing magnetic "noise" source such
as a passing car, truck, bus etc.  If unshielded....in a real way, it becomes kind of a seismo and a
rough weak "magnetometer" combination.
 
About the only "solution" is to encase the magnetic seismometer in a reasonably
shielded case; and even then it might be partially "iffy" for some signal noise you see.
 
In the sense of using magnetics as a question to extend the period of a mass....then
thats "the" question to explore.
 
Take care, Meredith
  
 


 
Subject: Volcano notice, flood from =?ISO-8859-1?Q?Grimsv=F6tn?= volcano From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 06 Dec 2007 21:41:25 +0000 Hi all It appears that flood has started from the Grimsv=F6tn Volcano system. This flood is peaking at this moment. It is unclear at present time if this is going to start a eruption like did happen in 2004, when last flood did happen. I will keep people posted if there is any intrest for it. I do not know if effects of eruptions are going to show on my sensor if there is a eruption. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? From: "meredith lamb" paleoartifact@......... Date: Thu, 6 Dec 2007 16:24:12 -0700 Hi Geoff, I tried a brief test on my steel "HD pivot vertical" which is basically like a "traditional" spring vertical; where opposing/repelling magnets were installed. The normal period of it was 2 seconds without magnets. I put a 1" ring magnet on the end of the test steel mass (facing to the front and centered). I put a larger disc (same, or repelling pole) magnet about 3" in front of it at about the same height. The steel base does interfere abit of course, as the magnet on the mass will have a attraction to the steel base underneath. Here, I added a smaller opposing magnet (you could call it a "bias" magnet), alittle in front and directly onto the steel base below the mass with its magnet. It was easy to move the magnet out front, to see where it either shortens the natural period (easy to do); or, lengthen the period. It takes abit of trial and error, but within afew minutes I could see a period of ~ 5 seconds. I'am guessing that with a better tweaking position arrangement, its quite possible to see even a longer period. The harmonic motion did hesitate abit on the downstroke peak. I'd expect the "bias" magnet would need tweaking there too....or, of course just use a aluminum base. The thought does occur, that the magnets could well limit or force the centering of the mass or perhaps help limit some of the spring temperature drift somewhat. Of course, trying to "somehow" still use a pickup coil on such, is likely out of the question. One would have to use a different sensor. Take care, Meredith On Dec 5, 2007 8:41 PM, Geoff wrote: > Hello PSN Folks; > > Has anyone ever used a spring > to take up most the mass weight then > maybe apply an ounce or less levitation > magnetically to set with electronics > the free period within a geophone. > > Id think you would pump a current limited signal > into the geophone and use some kind of > feedback circuit that might set > the free period. I am looking only > for a free period in the 3 to 4 second > range. > > If you take up the small weight with your hand > it seems you can move the hand up and down > at whatever period and the system will > not oppose what you are doing ?? > > Comments welcome. > > Regards > geoff > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >
Hi Geoff,
 
I tried a brief test on my steel "HD pivot vertical" which is basically like a "traditional"
spring vertical; where opposing/repelling magnets were installed.  The normal period
of it was 2 seconds without magnets.  
 
I put a 1" ring magnet on the end of the test steel mass (facing to the front and centered).
 
I put a larger disc (same, or repelling pole) magnet about 3" in front of it at about the
same height. 
 
The steel base does interfere abit of course, as the magnet on the mass will have
a attraction to the steel base underneath.  Here, I added a smaller opposing magnet
(you could call it a "bias" magnet), alittle in front and directly onto the steel base
below the mass with its magnet.
 
It was easy to move the magnet out front, to see where it either shortens
the natural period (easy to do); or, lengthen the period.  It takes abit of trial and
error, but within afew minutes I could see a period of ~ 5 seconds.  I'am guessing
that with a better tweaking position arrangement, its quite possible to see
even a longer period.
 
The harmonic motion did hesitate abit on the downstroke peak.  I'd expect the
"bias" magnet would need tweaking there too....or, of course just use a
aluminum base.
 
The thought does occur, that the magnets could well limit or force the centering
of the mass or perhaps help limit some of the spring temperature drift somewhat.
 
Of course, trying to "somehow" still use a pickup coil on such, is likely out of
the question.  One would have to use a different sensor.
 
Take care, Meredith
 
       

On Dec 5, 2007 8:41 PM, Geoff <gmvoeth@...........> wrote:
Hello PSN Folks;

Has anyone ever used a spring
to take up most the mass weight then
maybe apply an ounce or less levitation
magnetically to set with electronics
the free period within a geophone.

Id think you would pump a current limited signal
into the geophone and use some kind of
feedback circuit that might set
the free period. I am looking only
for a free period in the 3 to 4 second
range.

If you take up the small weight with your hand
it seems you can move the hand up and down
at whatever period and the system will
not oppose what you are doing ??

Comments welcome.

Regards
geoff
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.

Subject: Re: General Diamagnetic Tiltmeter Improvements From: Bobhelenmcclure@....... Date: Thu, 6 Dec 2007 21:39:47 EST Hi Meredith, Your setup reminds me of an experiment of mine I performed over two years ago. Like you, I used 3 Nd rectangular magnets and a pyrographite slab. I added 2 cube magnets near the ends to get a stable period. I put a 0.004" thick aluminum damping vane on top of the pyrographite. A small lens was mounted in the damping vane as part of a planned optical pickoff. The magnetic field for damping was furnished by four cube magnets on top of the structure. I never made the optical pickoff to complete the sensor, because tilt tests disclosed that the motion of the graphite was somewhat "sticky". I think small variations in the levitating magnetic fields are responsible. I tried thin iron shims in order to homogenize the field, but then the field was too weak to support levitation. It is my belief that iron pole pieces are necessary for the successful implementation of a diamagnetic seismometer/tiltmeter. Paramagnetism of the aluminum vane was a minor problem also. Cheers, Bob ************************************** Check out AOL's list of 2007's hottest products. (http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001) Hi Meredith,

  Your setup reminds me of an experiment of mine I performed over two y= ears ago. Like you, I used 3 Nd rectangular magnets and a pyrographite slab.= I added 2 cube magnets near the ends to get a stable period. I put a 0.004"= thick aluminum damping vane on top of the pyrographite. A small lens was mo= unted in the damping vane as part of a planned optical pickoff. The magnetic= field for damping was furnished by four cube magnets on top of the structur= e.

  I never made the optical pickoff to complete the sensor, because tilt= tests disclosed that the motion of the graphite was somewhat "sticky". I th= ink small variations in the levitating magnetic fields are responsible. I tr= ied thin iron shims in order to homogenize the field, but then the field was= too weak to support levitation. It is my belief that iron pole pieces are n= ecessary for the successful implementation of a diamagnetic seismometer/tilt= meter.

  Paramagnetism of the aluminum vane was a minor problem also.

Cheers,

Bob


**************************************
Check out AO= L's list of 2007's hottest products.
(http://money.aol.com/special/hot-pr= oducts-2007?NCID=3Daoltop00030000000001) Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? From: ChrisAtUpw@....... Date: Thu, 6 Dec 2007 22:15:18 EST In a message dated 06/12/2007, gmvoeth@........... writes: Has anyone ever used a spring to take up most the mass weight then maybe apply an ounce or less levitation magnetically to set with electronics the free period within a geophone. I'd think you would pump a current limited signal into the geophone and use some kind of feedback circuit that might set the free period. I am looking only for a free period in the 3 to 4 second range. Hi All, Trying to provide magnetic 'springs' for seismometers tends to quickly run into the problem of temperature coefficients and drifts. Alnico has the lowest Tc, being about -1 or -2 x10^-4 / C Deg depending on the grade. Sm-Co is about -3x10^-4 / C Deg and NdFeB is about -11x10^-4 / C Deg. Ferrite magnets are a lot worse. Sandwiches of thick Sm-Co and a thin opposing sheet of NdFeB have been used to provide ~high stability quadrupole magnets, but stabilising the temperature of the magnetic material is probably an easier option. The torsion coefficient of Steel Springs is about -2.6x10^-4 / C Deg. Only Elinvar and NiSpanC springs have very low coefficients in the ppm range. If you consider electromagnets, you have the problem of voltage reference drifts and amplifier drifts, as well as expansion coefficients and the thermal convection from heating. The common voltage reference diodes still have drifts of 20 to 150 ppm / C Deg. The few types with drifts in the low ppm range like the LM399 and LT1027 are quite expensive. Type 'prec ref' into _www.digikey.com_ (http://www.digikey.com) Weak springs were used to extend the period of the 1 to 3 second Willmore seismometers to about 20 seconds. These were produced in both vertical and horizontal versions. 'Trimming' of the period by magnetic repulsion has also been used on horizontal Lehman seismometers, but it can render them sensitive to stray magnetic field changes. A similar repulsion method has been used on clock pendulums to correct for period / swing angle timing errors. Trying to use the magnetic repulsion of pyrolitic graphite also tends to run into Tc problems as well as giving large stray magnetic fields. Geophones can have their natural periods very considerably extended (to <~1/20 natural frequency), if they are fitted with an amplifier with a negative input impedance roughly equal to their electrical resistance. The current generated by any motion is fed into a current to voltage converter and this output is proportional to frequency. The armature is effectively held stationary with respect to the case. A second amplifier stage with the output proportional to 1/f gives the normal velocity output. The sensitivity is quite low. These are described at _http://www.lennartz-electronic.de/PDF_documents/Seismometers.pdf_ (http://www.lennartz-electronic.de/PDF_documents/Seismometers.pdf) An alternative method also used by Lennartz is described by Roberts, P.M. 'A Versatile Equilization Circuit for Increasing Seismometer Velocity Response Below the Natural Frequency' BSSA Vol 79, no 4, pp 1607-1617 Oct. 1989 See also _http://jclahr.com/science/psn/roberts/index.html_ (http://jclahr.com/science/psn/roberts/index.html) This circuit selectively amplifies the f^2 'tail' of the normal geophone response below resonance and can provide a period extension of ~x10. Both types require the use of very low noise amplifiers, preferably with discreet matched pair low noise input transistors. Aaron Barzilai modified geophones by adding a capacitative position detector. See _http://micromachine.stanford.edu/smssl/projects/Geophones/ASMEWin'98FinalDraftSlides.pdf_ (http://micromachine.stanford.edu/smssl/projects/Geophones/ASMEWin'98FinalDraftSlides.pdf) and other references cited at _http://micromachine.stanford.edu/smssl/projects/Geophones/_ (http://micromachine.stanford.edu/smssl/projects/Geophones/) Unfortunately he seems to have used a difficult mechanical modification and his digital electronics, also described, was more noisy than it needed to be. Regards, Chris Chapman
In a message dated 06/12/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" color=3D#000000>Has anyone ever us= ed a=20 spring to take up most the mass weight then maybe apply an ounce or less=20 levitation magnetically to set with electronics the free period within a=20 geophone.

I'd think you would pump a current limited signal into th= e=20 geophone and use some kind of
feedback circuit that might set the free=20 period. I am looking only for a free period in the 3 to 4 second=20 range.
Hi All,
 
    Trying to provide magnetic 'springs' for=20 seismometers tends to quickly run into the problem of temperature coefficien= ts=20 and drifts. Alnico has the lowest Tc, being about -1 or -2 x10^-4 / C D= eg=20 depending on the grade. Sm-Co is about -3x10^-4 / C Deg and NdFeB is ab= out=20 -11x10^-4 / C Deg. Ferrite magnets are a lot worse.
    Sandwiches of thick Sm-Co and a thin opposing s= heet=20 of NdFeB have been used to provide ~high stability quadrupole magnets,=20= but=20 stabilising the temperature of the magnetic material is probably an easier=20 option.
    The torsion coefficient of Steel Springs is abo= ut=20 -2.6x10^-4 / C Deg. Only Elinvar and NiSpanC springs have very low coefficie= nts=20 in the ppm range.
    If you consider electromagnets, you have the=20 problem of voltage reference drifts and amplifier drifts, as well as expansi= on=20 coefficients and the thermal convection from heating. The common voltag= e=20 reference diodes still have drifts of 20 to 150 ppm / C Deg. The few types w= ith=20 drifts in the low ppm range like the LM399 and LT1027 are quite expensive. T= ype=20 'prec ref' into www.digikey.com
    Weak springs were used to extend the period of=20= the=20 1 to 3 second Willmore seismometers to about 20 seconds. These were produced= in=20 both vertical and horizontal versions. 'Trimming' of the period by magnetic=20 repulsion has also been used on horizontal Lehman seismometers, but it can=20 render them sensitive to stray magnetic field changes. A similar repuls= ion=20 method has been used on clock pendulums to correct for period / swing angle=20 timing errors. 
    Trying to use the magnetic repulsion of pyrolit= ic=20 graphite also tends to run into Tc problems as well as giving large stray=20 magnetic fields.
    Geophones can have their natural periods very=20 considerably extended (to <~1/20 natural frequency), if they are fitted w= ith=20 an amplifier with a negative input impedance roughly equal to their electric= al=20 resistance. The current generated by any motion is fed into a current to vol= tage=20 converter and this output is proportional to frequency. The=20 armature is effectively held stationary with respect to the case. A second=20 amplifier stage with the output proportional to 1/f gives the normal velocit= y=20 output. The sensitivity is quite low. These are described at ht= tp://www.lennartz-electronic.de/PDF_documents/Seismometers.pdf 
    An alternative method also used by Lennartz is=20 described by Roberts, P.M. 'A Versatile Equilization Circuit for=20 Increasing Seismometer Velocity Response Below the Natural=20 Frequency'  BSSA Vol 79, no 4, pp 1607-1617 Oct. 1989 See als= o http://jclahr.com/= science/psn/roberts/index.html This=20 circuit selectively amplifies the f^2 'tail' of the normal geophone=20 response below resonance and can provide a period extension of ~x10. Both ty= pes=20 require the use of very low noise amplifiers, preferably with discreet match= ed=20 pair low noise input transistors.
   Aaron Barzilai modified geophones by adding a=20 capacitative position detector. See http://micromachine.stanford.edu/smssl/projects/Geopho= nes/ASMEWin'98FinalDraftSlides.pdf and=20 other references cited at http://m= icromachine.stanford.edu/smssl/projects/Geophones/ Unfortunately=20 he seems to have used a difficult mechanical modification and his=20 digital electronics, also described, was more noisy than it needed to b= e.=20
 
    Regards,
 
    Chris Chapman
 Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Fri, 7 Dec 2007 14:12:05 -0700 Hi Bob, Thanks for your email note. It is real good to "hear" from someone with similar experiences. All your experiences do have a relevance; and many I've also seen in the past with this type of setup and other quite different variations. The "sticky" terminology in particular is that yes; it is normally a very real problem. It "seems", to be most visually prevalent when only a single piece of pyrolytic graphite is used. By "sticky" I mean it seems to sometimes be anchored in one or more spots and even with some light induced tilt where one would surely expect a movement response; they occasionally do not get any. Of course, I'am not referring to debris (small hair, etc.) that may actually be the cause sometimes. With PG, its possible to impart small magnetic particles thereon which will react in the magnetic fields of course. Actually the ONLY reason, I'am trying again is that with two separated but interconnected pieces of PG, I know I'am seeing quite a improvement in overall response. I can't really presently describe the "why"; except perhaps the joint sum of the two pieces are kind of like a differential diamagnetic response....or.....if this sounds right; it is kind of like a electronic resistance bridge were the voltage differential is seen in total, rather than in one partial sum segment resistor. Yes, I'am not a qualified scientist. I've also looked at totally switching out the PG, with other different pieces, and the results look the same; so its obviously not just specific to acouple PG pieces. Also, the PG pieces have been on and off the magnets numerious time for various test trials; so the results are real. The PG pieces are also fairly close to each other in dimensions; which might be necessary (?). The PG pieces I have are not precision machined so they vary in flatness and in other dimensions by around ~ 0.010". Another feature I like is the variable period with the variable PG spacing. How I'am going to do that with flimsy aluminum is yet to be attempted. One may have to settle for whatever period they select before any "glueing" down of the aluminum. Even being able to do so, is unique. I've even put a large optical magnifying lens next to the model; to check for minute lockups, and of course whether it physically oscillates around a reference "zero" mark I put on the magnet. I can't say I've definitely seen any sticking yet on this model; but if it happens, I will. One good indication that it works better is that I do see increased wider span tilt oscillation motion effects with the 2 PG pieces than I've ever seen with one piece of PG. It seems to be ~ 3X over that of just using 1 piece of PG. I don't yet really know the result of adding on steel/iron atop the magnets; as I've not yet done so. I think I'll try 1/2" width X 1/8" thick iron initially. The iron is commercially common size stuff, but it does have dual rounded outer width edges; which might not be totally ideal. The size is common; but its different, as it was used as a desk drawer guide and was coated with a thin layer of copper and then chrome plated. Its probably (?) bright steel and not the black structural variety. I've seen thin ~ 1/16" thick iron/steel work very well on kind of a "U" channel type setup...where the (then) spectrographite rod levitated lower down on the deliberately lower middle channel magnet. That was Chris's recommendation and it did dramatically improve its levitation height. Yes; the aluminum paramagnetism has been seen in the past also; and its going to show up here also. The aluminum could be responsible for some of the sticking, with their various impurities. I'am using K&S Engineering aluminum; which seems to be purer stuff. With the severe weight limitations; its hard to consider using other metal/s. I suppose I can hang up a piece of the stuff on a long thread, and bring a magnet near it; to just see a rough indication of its general paramagnetism. I am also presently using 2 plastic spacers inbetween the magnets; which are 0.035" thick X ~0.475" in width. The spacer is a idea from John Lahr; and it does help alittle for some slightly increased levitation. I may try to find some thin plastic or non-ferrious metal that is 5/8" in width and somewhere around 0.020 to 0.0315" thick, that could aid in setting up the iron on the magnet tops. The iron will be magnetically normally forced against the joints for alignment. If I don't glue and leave it as is; then if it doesn't work too well; I can easily remove the iron and go on from there. Of course; I don't know yet know how it will all turn out; but....its all fun stuff to just see what happens. Take care, Meredith On Dec 6, 2007 7:39 PM, wrote: > Hi Meredith, > > Your setup reminds me of an experiment of mine I performed over two > years ago. Like you, I used 3 Nd rectangular magnets and a pyrographite > slab. I added 2 cube magnets near the ends to get a stable period. I put a > 0.004" thick aluminum damping vane on top of the pyrographite. A small > lens was mounted in the damping vane as part of a planned optical pickoff. > The magnetic field for damping was furnished by four cube magnets on top of > the structure. > > I never made the optical pickoff to complete the sensor, because tilt > tests disclosed that the motion of the graphite was somewhat "sticky". I > think small variations in the levitating magnetic fields are responsible. I > tried thin iron shims in order to homogenize the field, but then the field > was too weak to support levitation. It is my belief that iron pole pieces > are necessary for the successful implementation of a diamagnetic > seismometer/tiltmeter. > > Paramagnetism of the aluminum vane was a minor problem also. > > Cheers, > > Bob > > > >
Hi Bob,
 
Thanks for your email note.  It is real good to "hear" from someone with similar experiences.
 
All your experiences do have a relevance; and many I've also seen in the past with this type of setup
and other quite different variations.
 
The "sticky" terminology in particular is that yes; it is normally a very real problem.  It "seems", to be
most visually prevalent when only a single piece of pyrolytic graphite is used.  By "sticky" I mean it
seems to sometimes be anchored in one or more spots and even with some light induced tilt where
one would surely expect a movement response; they occasionally do not get any.  Of course, I'am
not referring to debris (small hair, etc.) that may actually be the cause sometimes.  With PG, its
possible to impart small magnetic particles thereon which will react in the magnetic fields of course.
 
Actually the ONLY reason, I'am trying again is that with two separated but interconnected pieces of
PG, I know I'am seeing quite a improvement in overall response.  I can't really presently describe the
"why"; except perhaps the joint sum of the two pieces are kind of like a differential diamagnetic
response....or.....if this sounds right; it is kind of like a electronic resistance bridge were the voltage
differential is seen in total, rather than in one partial sum segment resistor.  Yes, I'am not a qualified
scientist.  I've also looked at totally switching out the PG, with other different pieces, and the results
look the same; so its obviously not just specific to acouple PG pieces.  Also, the PG pieces have
been on and off the magnets numerious time for various test trials; so the results are real.  The PG
pieces are also fairly close to each other in dimensions; which might be necessary (?).  The PG
pieces I have are not precision machined so they vary in flatness and in other dimensions by around
~ 0.010".
 
Another feature I like is the variable period with the variable PG spacing.  How I'am going to do that
with flimsy aluminum is yet to be attempted.  One may have to settle for whatever period they select
before any "glueing" down of the aluminum.  Even being able to do so, is unique.
 
I've even put a large optical magnifying lens next to the model; to check for minute lockups, and
of course whether it physically oscillates around a reference "zero" mark I put on the magnet.  I can't
say I've definitely seen any sticking yet on this model; but if it happens, I will.
 
One good indication that it works better is that I do see increased wider span tilt oscillation motion
effects with the 2 PG pieces than I've ever seen with one piece of PG.  It seems to be ~ 3X over
that of just using 1 piece of PG.
 
I don't yet really know the result of adding on steel/iron atop the magnets; as I've not yet done so.
I think I'll try 1/2" width X 1/8" thick iron initially.  The iron is commercially common size stuff, but
it does have dual rounded outer width edges; which might not be totally ideal.  The size is common;
but its different, as it was used as a desk drawer guide and was coated with a thin layer of copper
and then chrome plated.  Its probably (?) bright steel and not the black structural variety.
 
I've seen thin ~ 1/16" thick iron/steel work very well on kind of a "U" channel type setup...where the
(then) spectrographite rod levitated lower down on the deliberately lower middle channel magnet.
That was Chris's recommendation and it did dramatically improve its levitation height. 
 
Yes; the aluminum paramagnetism has been seen in the past also; and its going to show up here
also.  The aluminum could be responsible for some of the sticking, with their various impurities.
I'am using K&S Engineering aluminum; which seems to be purer stuff.  With the severe weight
limitations; its hard to consider using other metal/s.  I suppose I can hang up a piece of the stuff
on a long thread, and bring a magnet near it; to just see a rough indication of its general paramagnetism.
 
I am also presently using 2 plastic spacers inbetween the magnets; which are 0.035" thick X ~0.475"
in width.  The spacer is a idea from John Lahr; and it does help alittle for some slightly increased
levitation.  I may try to find some thin plastic or non-ferrious metal that is 5/8" in width and somewhere
around 0.020 to 0.0315" thick, that could aid in setting up the iron on the magnet tops.  The iron will
be magnetically normally forced against the joints for alignment.  If I don't glue and leave it as is; then
if it doesn't work too well; I can easily remove the iron and go on from there.
 
Of course; I don't know yet know how it will all turn out; but....its all fun stuff to just see what happens.
 
Take care, Meredith  
On Dec 6, 2007 7:39 PM, <Bobhelenmcclure@.......> wrote:
Hi Meredith,

  Your setup reminds me of an experiment of mine I performed over two years ago. Like you, I used 3 Nd rectangular magnets and a pyrographite slab. I added 2 cube magnets near the ends to get a stable period. I put a 0.004" thick aluminum damping vane on top of the pyrographite. A small lens was mounted in the damping vane as part of a planned optical pickoff. The magnetic field for damping was furnished by four cube magnets on top of the structure.


  I never made the optical pickoff to complete the sensor, because tilt tests disclosed that the motion of the graphite was somewhat "sticky". I think small variations in the levitating magnetic fields are responsible. I tried thin iron shims in order to homogenize the field, but then the field was too weak to support levitation. It is my belief that iron pole pieces are necessary for the successful implementation of a diamagnetic seismometer/tiltmeter.

  Paramagnetism of the aluminum vane was a minor problem also.

Cheers,

Bob



 
Subject: Re: General Diamagnetic Tiltmeter Improvements From: ChrisAtUpw@....... Date: Fri, 7 Dec 2007 19:07:17 EST In a message dated 07/12/2007, paleoartifact@......... writes: The "sticky" terminology in particular is that yes; it is normally a very real problem. It "seems", to be most visually prevalent when only a single piece of pyrolytic graphite is used. By "sticky" I mean it seems to sometimes be anchored in one or more spots and even with some light induced tilt where one would surely expect a movement response; they occasionally do not get any. Of course, I'am not referring to debris (small hair, etc.) that may actually be the cause sometimes. With PG, its possible to impart small magnetic particles thereon which will react in the magnetic fields of course. Hi Meredith, I suspect that this is due to slightly differing field strengths along the magnets. It is very troublesome when you are using several magnets joined in line. Actually the ONLY reason, I'am trying again is that with two separated but interconnected pieces of PG, I know I'am seeing quite a improvement in overall response. I can't really presently describe the "why"; except perhaps the joint sum of the two pieces are kind of like a differential diamagnetic response.... The sum of two pieces should help smooth out local magnetic fluctuations. I've also looked at totally switching out the PG, with other different pieces, and the results look the same; so its obviously not just specific to acouple PG pieces. Also, the PG pieces have been on and off the magnets numerious time for various test trials; so the results are real. The PG pieces are also fairly close to each other in dimensions; which might be necessary (?). The PG pieces I have are not precision machined so they vary in flatness and in other dimensions by around ~ 0.010". You might try using emery paper on a flat surface to give a flat under surface to the PG pieces? Another feature I like is the variable period with the variable PG spacing. How I'am going to do that with flimsy aluminum is yet to be attempted. One may have to settle for whatever period they select before any "glueing" down of the aluminum. Even being able to do so, is unique. Can you buy some copper foil from K&S Metals and use that? They stock 3 and 5 thou sheet. The Aluminum usually supplied is a Si alloy, not pure and it is paramagnetic. Copper is diamagnetic but far weaker. I ran up against these differences / problems when using NdFeB quad magnets for damping the Lehman. I've even put a large optical magnifying lens next to the model; to check for minute lockups, and of course whether it physically oscillates around a reference "zero" mark I put on the magnet. I can't say I've definitely seen any sticking yet on this model; but if it happens, I will. If you use a small lens to give a ~parallel light beam from a small bulb at rignt angles to the slip direction, small side movements probably won't be too obvious. One good indication that it works better is that I do see increased wider span tilt oscillation motion effects with the 2 PG pieces than I've ever seen with one piece of PG. It seems to be ~ 3X over that of just using 1 piece of PG. I don't yet really know the result of adding on steel/iron atop the magnets; as I've not yet done so. I think I'll try 1/2" width X 1/8" thick iron initially. The iron is commercially common size stuff, but it does have dual rounded outer width edges; which might not be totally ideal. The size is common; but its different, as it was used as a desk drawer guide and was coated with a thin layer of copper and then chrome plated. Its probably (?) bright steel and not the black structural variety. I've seen thin ~ 1/16" thick iron/steel work very well on kind of a "U" channel type setup...where the (then) spectrographite rod levitated lower down on the deliberately lower middle channel magnet. That was Chris's recommendation and it did dramatically improve its levitation height. I bought some 1/32" galvanised steel sheet, which seemed to work quite well. I suspect that 1/8" will be much too thick and it will allow the field to be linked sideways, instead of looped over the top of the magnets and going through the graphite. Iron will carry about twice the field that the magnet can supply. You might consider filing the edges of the strips at 45 degrees, rather than leaving it at a right angle? Yes; the aluminum paramagnetism has been seen in the past also; and its going to show up here also. The aluminum could be responsible for some of the sticking, with their various impurities. I am using K&S Engineering aluminum; which seems to be purer stuff. With the severe weight limitations; its hard to consider using other metal/s. I suppose I can hang up a piece of the stuff on a long thread, and bring a magnet near it; to just see a rough indication of its general paramagnetism. K&S supply mostly 6061 Al alloy See _www.ksmetals.com_ (http://www.ksmetals.com) and _http://en.wikipedia.org/wiki/6061_aluminum_ (http://en.wikipedia.org/wiki/6061_aluminum) I am also presently using 2 plastic spacers in between the magnets; which are 0.035" thick X ~0.475" in width. The spacer is a idea from John Lahr; and it does help a little for some slightly increased levitation. I may try to find some thin plastic or non-ferrious metal that is 5/8" in width and somewhere around 0.020 to 0.0315" thick, that could aid in setting up the iron on the magnet tops. The iron will be magnetically normally forced against the joints for alignment. Regards, Chris Chapman
In a message dated 07/12/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
The "sticky" terminology in particular is that yes; it is normally a=20= very=20 real problem.  It "seems", to be most visually prevalent when only a=20 single piece of pyrolytic graphite is used.  By "sticky" I mean it se= ems=20 to sometimes be anchored in one or more spots and even with some light ind= uced=20 tilt where one would surely expect a movement response; they occasionally=20= do=20 not get any.  Of course, I'am not referring to debris (small hair, et= c.)=20 that may actually be the cause sometimes.  With PG, its possible to=20 impart small magnetic particles thereon which will react in the magnetic=20 fields of course.
Hi Meredith,
 
    I suspect that this is due to slightly differin= g=20 field strengths along the magnets. It is very troublesome when you are using= =20 several magnets joined in line.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Actually the ONLY reason, I'am trying again is that with two separate= d=20 but interconnected pieces of
PG, I know I'am seeing quite a improvement in overall response. = I=20 can't really presently describe the "why"; except perhaps the joint sum of= the=20 two pieces are kind of like a differential diamagnetic
response....
    The sum of two pieces should help smooth out lo= cal=20 magnetic fluctuations. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
 I've also looked at totally switching out the PG, with other=20 different pieces, and the results
look the same; so its obviously not just specific to acouple PG=20 pieces.  Also, the PG pieces have
been on and off the magnets numerious time for various test trials; s= o=20 the results are real.  The PG
pieces are also fairly close to each other in dimensions; which might= be=20 necessary (?).  The PG
pieces I have are not precision machined so they vary in flatness and= in=20 other dimensions by around
~ 0.010".
    You might try using emery paper on a flat surfa= ce=20 to give a flat under surface to the PG pieces? 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Another feature I like is the variable period with the variable PG=20 spacing.  How I'am going to do that
with flimsy aluminum is yet to be attempted.  One may have to se= ttle=20 for whatever period they select before any "glueing" down of the=20 aluminum.  Even being able to do so, is unique.
    Can you buy some copper foil from K&S Metal= s=20 and use that? They stock 3 and 5 thou sheet. The Aluminum usually supplied i= s a=20 Si alloy, not pure and it is paramagnetic. Copper is diamagnetic but=20 far weaker. I ran up against these differences / problems when using Nd= FeB=20 quad magnets for damping the Lehman.   
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I've even put a large optical magnifying lens next to the model; to c= heck=20 for minute lockups, and
of course whether it physically oscillates around a reference "zero"=20= mark=20 I put on the magnet.  I can't say I've definitely seen any sticking y= et=20 on this model; but if it happens, I will.
    If you use a small lens to give a ~parallel lig= ht=20 beam from a small bulb at rignt angles to the slip direction, small sid= e=20 movements probably won't be too obvious. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
One good indication that it works better is that I do see increased w= ider=20 span tilt oscillation motion
effects with the 2 PG pieces than I've ever seen with one piece of=20 PG.  It seems to be ~ 3X over
that of just using 1 piece of PG.
 
I don't yet really know the result of adding on steel/iron atop=20= the=20 magnets; as I've not yet done so.
I think I'll try 1/2" width X 1/8" thick iron initially.  The ir= on=20 is commercially common size stuff, but
it does have dual rounded outer width edges; which might not be total= ly=20 ideal.  The size is common;
but its different, as it was used as a desk drawer guide and was coat= ed=20 with a thin layer of copper
and then chrome plated.  Its probably (?) bright steel and not t= he=20 black structural variety.
 
I've seen thin ~ 1/16" thick iron/steel work very well on kind of a "= U"=20 channel type setup...where the
(then) spectrographite rod levitated lower down on the deliberately l= ower=20 middle channel magnet.
That was Chris's recommendation and it did dramatically improve its=20 levitation height. 
    I bought some 1/32" galvanised steel sheet, whi= ch=20 seemed to work quite well. I suspect that 1/8" will be much too thick and it= =20 will allow the field to be linked sideways, instead of looped over the top o= f=20 the magnets and going through the graphite. Iron will carry about twice the=20 field that the magnet can supply. You might consider filing the edges of the= =20 strips at 45 degrees, rather than leaving it at a right angle?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Yes; the aluminum paramagnetism has been seen in the past also; and=20 its going to show up here
also.  The aluminum could be responsible for some of the stickin= g,=20 with their various impurities.
I am using K&S Engineering aluminum; which seems to be purer=20 stuff.  With the severe weight
limitations; its hard to consider using other metal/s.  I suppos= e I=20 can hang up a piece of the stuff
on a long thread, and bring a magnet near it; to just see a rough=20 indication of its general paramagnetism.
    K&S supply mostly 6061 Al alloy
    See www.ksmetals.com and http://en.wikipedia.org/= wiki/6061_aluminum=20
    
I am also presently using 2 plastic spacers in between the magnets;= which=20 are 0.035" thick X ~0.475" in width.  The spacer is a idea from Jo= hn=20 Lahr; and it does help a little for some slightly increased levitation. = ;=20 I may try to find some thin plastic or non-ferrious metal that is 5/8"=20= in=20 width and somewhere around 0.020 to 0.0315" thick, that could aid in setting= =20 up the iron on the magnet tops.  The iron will be magnetically=20 normally forced against the joints for alignment.
 
    Regards,
    
    Chris Chapman
Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Fri, 7 Dec 2007 22:54:15 -0700 Hi Chris, Thanks for all the notes, I'am planning on trying most if not all in time. I did whip up 3 strapping steel units of a thickness of 0.022" and put them on the magnets, with plastic spacers, but without any beveled inside edges. I am seeing a levitation height of ~ 0.020"; which appears to be ~ 0.005" of a inch less than without any steel whatsoever on top. Out of curiosity, I removed the center iron strip. Now, the levitation height is about 0.025" above the 2 outside steel strips. This also means (for what its worth); that its levitation height above the center magnet to the bottom of the PG is a interesting ~.047"....which is almost twice the average levitation height with no steel at all. In a terminology way; its kind of a "U" channel setup in this configuration. Of course, adding weight to the PG, is still limited to less than 0.025". Totally unexpected but a interesting and possibly useful result...which opens up yet more thought/s of additional changes. The harmonic oscillation motion does appears to be much more symetrical; than I think I've seen it before....so, it appears the iron is doing some good. I'd think that some "weight load" tests might be appropriate for both variations. Take care, Meredith On Dec 7, 2007 5:07 PM, wrote: > In a message dated 07/12/2007, paleoartifact@......... writes: > > The "sticky" terminology in particular is that yes; it is normally a very > real problem. It "seems", to be most visually prevalent when only a single > piece of pyrolytic graphite is used. By "sticky" I mean it seems to > sometimes be anchored in one or more spots and even with some light induced > tilt where one would surely expect a movement response; they occasionally do > not get any. Of course, I'am not referring to debris (small hair, etc.) > that may actually be the cause sometimes. With PG, its possible to impart > small magnetic particles thereon which will react in the magnetic fields of > course. > > Hi Meredith, > > I suspect that this is due to slightly differing field strengths along > the magnets. It is very troublesome when you are using several magnets > joined in line. > > Actually the ONLY reason, I'am trying again is that with two separated but > interconnected pieces of > PG, I know I'am seeing quite a improvement in overall response. I can't > really presently describe the "why"; except perhaps the joint sum of the two > pieces are kind of like a differential diamagnetic > response.... > > The sum of two pieces should help smooth out local magnetic > fluctuations. > > I've also looked at totally switching out the PG, with other different > pieces, and the results > look the same; so its obviously not just specific to acouple PG pieces. > Also, the PG pieces have > been on and off the magnets numerious time for various test trials; so the > results are real. The PG > pieces are also fairly close to each other in dimensions; which might be > necessary (?). The PG > pieces I have are not precision machined so they vary in flatness and in > other dimensions by around > ~ 0.010". > > You might try using emery paper on a flat surface to give a flat under > surface to the PG pieces? > > Another feature I like is the variable period with the variable PG > spacing. How I'am going to do that > with flimsy aluminum is yet to be attempted. One may have to settle for > whatever period they select before any "glueing" down of the aluminum. Even > being able to do so, is unique. > > Can you buy some copper foil from K&S Metals and use that? They stock > 3 and 5 thou sheet. The Aluminum usually supplied is a Si alloy, not > pure and it is paramagnetic. Copper is diamagnetic but far weaker. I ran up > against these differences / problems when using NdFeB quad magnets for > damping the Lehman. > > I've even put a large optical magnifying lens next to the model; to check > for minute lockups, and > of course whether it physically oscillates around a reference "zero" mark > I put on the magnet. I can't say I've definitely seen any sticking yet on > this model; but if it happens, I will. > > If you use a small lens to give a ~parallel light beam from a small > bulb at rignt angles to the slip direction, small side movements probably > won't be too obvious. > > One good indication that it works better is that I do see increased wider > span tilt oscillation motion > effects with the 2 PG pieces than I've ever seen with one piece of PG. It > seems to be ~ 3X over > that of just using 1 piece of PG. > > I don't yet really know the result of adding on steel/iron atop the > magnets; as I've not yet done so. > I think I'll try 1/2" width X 1/8" thick iron initially. The iron is > commercially common size stuff, but > it does have dual rounded outer width edges; which might not be totally > ideal. The size is common; > but its different, as it was used as a desk drawer guide and was coated > with a thin layer of copper > and then chrome plated. Its probably (?) bright steel and not the black > structural variety. > > I've seen thin ~ 1/16" thick iron/steel work very well on kind of a "U" > channel type setup...where the > (then) spectrographite rod levitated lower down on the deliberately lower > middle channel magnet. > That was Chris's recommendation and it did dramatically improve its > levitation height. > > I bought some 1/32" galvanised steel sheet, which seemed to work quite > well. I suspect that 1/8" will be much too thick and it will allow the field > to be linked sideways, instead of looped over the top of the magnets and > going through the graphite. Iron will carry about twice the field that the > magnet can supply. You might consider filing the edges of the strips at 45 > degrees, rather than leaving it at a right angle? > > Yes; the aluminum paramagnetism has been seen in the past also; and > its going to show up here > also. The aluminum could be responsible for some of the sticking, with > their various impurities. > I am using K&S Engineering aluminum; which seems to be purer stuff. With > the severe weight > limitations; its hard to consider using other metal/s. I suppose I can > hang up a piece of the stuff > on a long thread, and bring a magnet near it; to just see a rough > indication of its general paramagnetism. > > K&S supply mostly 6061 Al alloy > See www.ksmetals.com and http://en.wikipedia.org/wiki/6061_aluminum > > I am also presently using 2 plastic spacers in between the magnets; which > are 0.035" thick X ~0.475" in width. The spacer is a idea from John Lahr; > and it does help a little for some slightly increased levitation. I may try > to find some thin plastic or non-ferrious metal that is 5/8" in width and > somewhere around 0.020 to 0.0315" thick, that could aid in setting up the > iron on the magnet tops. The iron will be magnetically normally forced > against the joints for alignment. > > Regards, > > Chris Chapman >
Hi Chris,
 
Thanks for all the notes, I'am planning on trying most if not all in time.
 
I did whip up 3 strapping steel units of a thickness of 0.022" and put them
on the magnets, with plastic spacers, but without any beveled inside edges.
I am seeing a levitation height of ~ 0.020"; which appears to be ~ 0.005"
of a inch less than without any steel whatsoever on top.
 
Out of curiosity, I removed the center iron strip.  Now, the levitation height
is about 0.025" above the 2 outside steel strips.  This also means (for what its
worth); that its levitation height above the center magnet to the bottom of the PG
is a interesting ~.047"....which is almost twice the average levitation height with
no steel at all.  In a terminology way; its kind of a "U" channel setup in this
configuration.  Of course, adding weight to the PG, is still limited to less than 0.025". 
Totally unexpected but a interesting and possibly useful result...which opens up
yet more thought/s of additional changes. 
 
The harmonic oscillation motion does appears to be much more symetrical;
than I think I've seen it before....so, it appears the iron is doing some good.
 
I'd think that some "weight load" tests might be appropriate for both variations.
 
Take care, Meredith

 
On Dec 7, 2007 5:07 PM, <ChrisAtUpw@.......> wrote:
In a message dated 07/12/2007, paleoartifact@......... writes:
The "sticky" terminology in particular is that yes; it is normally a very real problem.  It "seems", to be most visually prevalent when only a single piece of pyrolytic graphite is used.  By "sticky" I mean it seems to sometimes be anchored in one or more spots and even with some light induced tilt where one would surely expect a movement response; they occasionally do not get any.  Of course, I'am not referring to debris (small hair, etc.) that may actually be the cause sometimes.  With PG, its possible to impart small magnetic particles thereon which will react in the magnetic fields of course.
Hi Meredith,
 
    I suspect that this is due to slightly differing field strengths along the magnets. It is very troublesome when you are using several magnets joined in line.
Actually the ONLY reason, I'am trying again is that with two separated but interconnected pieces of
PG, I know I'am seeing quite a improvement in overall response.  I can't really presently describe the "why"; except perhaps the joint sum of the two pieces are kind of like a differential diamagnetic
response....
    The sum of two pieces should help smooth out local magnetic fluctuations. 
 I've also looked at totally switching out the PG, with other different pieces, and the results
look the same; so its obviously not just specific to acouple PG pieces.  Also, the PG pieces have
been on and off the magnets numerious time for various test trials; so the results are real.  The PG
pieces are also fairly close to each other in dimensions; which might be necessary (?).  The PG
pieces I have are not precision machined so they vary in flatness and in other dimensions by around
~ 0.010".
    You might try using emery paper on a flat surface to give a flat under surface to the PG pieces? 
Another feature I like is the variable period with the variable PG spacing.  How I'am going to do that
with flimsy aluminum is yet to be attempted.  One may have to settle for whatever period they select before any "glueing" down of the aluminum.  Even being able to do so, is unique.
    Can you buy some copper foil from K&S Metals and use that? They stock 3 and 5 thou sheet. The Aluminum usually supplied is a Si alloy, not pure and it is paramagnetic. Copper is diamagnetic but far weaker. I ran up against these differences / problems when using NdFeB quad magnets for damping the Lehman.   
I've even put a large optical magnifying lens next to the model; to check for minute lockups, and
of course whether it physically oscillates around a reference "zero" mark I put on the magnet.  I can't say I've definitely seen any sticking yet on this model; but if it happens, I will.
    If you use a small lens to give a ~parallel light beam from a small bulb at rignt angles to the slip direction, small side movements probably won't be too obvious. 
One good indication that it works better is that I do see increased wider span tilt oscillation motion
effects with the 2 PG pieces than I've ever seen with one piece of PG.  It seems to be ~ 3X over
that of just using 1 piece of PG.
 
I don't yet really know the result of adding on steel/iron atop the magnets; as I've not yet done so.
I think I'll try 1/2" width X 1/8" thick iron initially.  The iron is commercially common size stuff, but
it does have dual rounded outer width edges; which might not be totally ideal.  The size is common;
but its different, as it was used as a desk drawer guide and was coated with a thin layer of copper
and then chrome plated.  Its probably (?) bright steel and not the black structural variety.
 
I've seen thin ~ 1/16" thick iron/steel work very well on kind of a "U" channel type setup...where the
(then) spectrographite rod levitated lower down on the deliberately lower middle channel magnet.
That was Chris's recommendation and it did dramatically improve its levitation height. 
    I bought some 1/32" galvanised steel sheet, which seemed to work quite well. I suspect that 1/8" will be much too thick and it will allow the field to be linked sideways, instead of looped over the top of the magnets and going through the graphite. Iron will carry about twice the field that the magnet can supply. You might consider filing the edges of the strips at 45 degrees, rather than leaving it at a right angle?
Yes; the aluminum paramagnetism has been seen in the past also; and its going to show up here
also.  The aluminum could be responsible for some of the sticking, with their various impurities.
I am using K&S Engineering aluminum; which seems to be purer stuff.  With the severe weight
limitations; its hard to consider using other metal/s.  I suppose I can hang up a piece of the stuff
on a long thread, and bring a magnet near it; to just see a rough indication of its general paramagnetism.
    K&S supply mostly 6061 Al alloy
    See www.ksmetals.com and http://en.wikipedia.org/wiki/6061_aluminum
    
I am also presently using 2 plastic spacers in between the magnets; which are 0.035" thick X ~0.475" in width.  The spacer is a idea from John Lahr; and it does help a little for some slightly increased levitation.  I may try to find some thin plastic or non-ferrious metal that is 5/8" in width and somewhere around 0.020 to 0.0315" thick, that could aid in setting up the iron on the magnet tops.  The iron will be magnetically normally forced against the joints for alignment.
 
    Regards,
    
    Chris Chapman

Subject: Re: General Diamagnetic Tiltmeter Improvements From: ChrisAtUpw@....... Date: Sat, 8 Dec 2007 09:51:51 EST In a message dated 08/12/2007, paleoartifact@......... writes: I did whip up 3 strapping steel units of a thickness of 0.022" and put them on the magnets, with plastic spacers, but without any beveled inside edges. I am seeing a levitation height of ~ 0.020"; which appears to be ~ 0.005" of a inch less than without any steel whatsoever on top. Hi Meredith, Instead of having the outer two strips coming to the exact edge of the magnets, try backing them off say 20 thou, then 40 thou? See if this improves matters? Out of curiosity, I removed the center iron strip. Now, the levitation height is about 0.025" above the 2 outside steel strips. This also means (for what its worth); that its levitation height above the center magnet to the bottom of the PG is a interesting ~.047"....which is almost twice the average levitation height with no steel at all. In a terminology way; its kind of a "U" channel setup in this configuration. What happens with the centre strip in place, but the two outer strips backed off / removed entirely? I suggest that you try narrowing the centre strip maybe 20 thou / 40 thou and bevelling the edges? You could use pencil leads for joining the graphite strips? Maybe plastic drinking straws? Then you would likely need much less Al or Cu for the damping plate? Regards, Chris
In a message dated 08/12/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I did whip up 3 strapping steel units of a thickness of 0.022" a= nd=20 put them
on the magnets, with plastic spacers, but without any beveled inside=20 edges.
I am seeing a levitation height of ~ 0.020"; which appears to be = ;~=20 0.005"
of a inch less than without any steel whatsoever on=20 top.
Hi Meredith,
 
    Instead of having the outer two strips coming t= o=20 the exact edge of the magnets, try backing them off say 20 thou, then 40=20 thou? See if this improves matters?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Out of curiosity, I removed the center iron strip.  Now, th= e=20 levitation height
is about 0.025" above the 2 outside steel strips.  This also mea= ns=20 (for what its
worth); that its levitation height above the center magnet to the bot= tom=20 of the PG
is a interesting ~.047"....which is almost twice the average levitati= on=20 height with
no steel at all.  In a terminology way; its kind of a "U" channe= l=20 setup in this
configuration. 
    What happens with the centre strip in place, bu= t=20 the two outer strips backed off / removed entirely?
 
    I suggest that you try narrowing the centre str= ip=20 maybe 20 thou / 40 thou and bevelling the edges?
 
    You could use pencil leads for joining the grap= hite=20 strips? Maybe plastic drinking straws? Then you would likely need much less=20= Al=20 or Cu for the damping plate?
 
    Regards,
 
    Chris
 
Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Sat, 8 Dec 2007 11:15:55 -0700 Hi Chris, I used a handy strene strip with a thickness of 0.022" (matches the thickness of the steel), but it was 0.112" wide; and used that to back off the two outer plates away from the center magnet. Here the levitation height of the PG was ~ 0.018". Thats about 0.007" less than with no steel roughly. I tried only having the center magnet steel in place, and got a levitation height of ~ 0.013"; and yes it still levitated. I crudely checked last night the weight lifting ability, with acouple variations of iron sheet and it seems to reduce the added weight lift capability anywhere from half to 2/3rds from that with no steel. Bob was right....iron kills...ha. Irons helps smooth the magnetic field nevertheless. All in all; it seems that any final model will eventually end up as a compromise of all the factors involved....not near perfect, in all aspects. Yes; diamagnetic pencil leads, are probably the best "interconnection" or "flag" extension choice. With their uniform diamagnetic lift response, they also tend to center the PG in its path for improved linarity and some minor reduced perpendicular "noise" response. I do have some K&S 0.005" thick copper sheet I could try for dampening. Beveling steel edges is yet to come. I do wonder about even thinner steel sheet.... Take care, Meredith On Dec 8, 2007 7:51 AM, wrote: > In a message dated 08/12/2007, paleoartifact@......... writes: > > I did whip up 3 strapping steel units of a thickness of 0.022" and put > them > on the magnets, with plastic spacers, but without any beveled inside > edges. > I am seeing a levitation height of ~ 0.020"; which appears to be ~ 0.005" > of a inch less than without any steel whatsoever on top. > > Hi Meredith, > > Instead of having the outer two strips coming to the exact edge of the > magnets, try backing them off say 20 thou, then 40 thou? See if this > improves matters? > > Out of curiosity, I removed the center iron strip. Now, the levitation > height > is about 0.025" above the 2 outside steel strips. This also means (for > what its > worth); that its levitation height above the center magnet to the bottom > of the PG > is a interesting ~.047"....which is almost twice the average levitation > height with > no steel at all. In a terminology way; its kind of a "U" channel setup in > this > configuration. > > What happens with the centre strip in place, but the two outer strips > backed off / removed entirely? > > I suggest that you try narrowing the centre strip maybe 20 thou / 40 > thou and bevelling the edges? > > You could use pencil leads for joining the graphite strips? Maybe > plastic drinking straws? Then you would likely need much less Al or Cu for > the damping plate? > > Regards, > > Chris > >
Hi Chris,
 
I used a handy strene strip with a thickness of 0.022" (matches the thickness of the steel),
but it was 0.112" wide; and used that to back off the two outer plates away from the center
magnet.  Here the levitation height of the PG was ~ 0.018".  Thats about 0.007" less than
with no steel roughly.
 
I tried only having the center magnet steel in place, and got a levitation height of ~ 0.013";
and yes it still levitated.
 
I crudely checked last night the weight lifting ability, with acouple variations of iron sheet
and it seems to reduce the added weight lift capability anywhere from half to 2/3rds from
that with no steel.  Bob was right....iron kills...ha.  Irons helps smooth the magnetic field
nevertheless.  All in all; it seems that any final model will eventually end up as a compromise
of all the factors involved....not near perfect, in all aspects.
 
Yes; diamagnetic pencil leads, are probably the best "interconnection" or "flag"
extension choice.  With their uniform diamagnetic lift response, they also tend to center
the PG in its path for improved linarity and some minor reduced perpendicular "noise"
response. 
 
I do have some K&S 0.005" thick copper sheet I could try for dampening. 
 
Beveling steel edges is yet to come.
 
I do wonder about even thinner steel sheet....
 
Take care, Meredith
 
 
 

On Dec 8, 2007 7:51 AM, <ChrisAtUpw@.......> wrote:
In a message dated 08/12/2007, paleoartifact@......... writes:
I did whip up 3 strapping steel units of a thickness of 0.022" and put them
on the magnets, with plastic spacers, but without any beveled inside edges.
I am seeing a levitation height of ~ 0.020"; which appears to be ~ 0.005"
of a inch less than without any steel whatsoever on top.
Hi Meredith,
 
    Instead of having the outer two strips coming to the exact edge of the magnets, try backing them off say 20 thou, then 40 thou? See if this improves matters?
Out of curiosity, I removed the center iron strip.  Now, the levitation height
is about 0.025" above the 2 outside steel strips.  This also means (for what its
worth); that its levitation height above the center magnet to the bottom of the PG
is a interesting ~.047"....which is almost twice the average levitation height with
no steel at all.  In a terminology way; its kind of a "U" channel setup in this
configuration. 
    What happens with the centre strip in place, but the two outer strips backed off / removed entirely?
 
    I suggest that you try narrowing the centre strip maybe 20 thou / 40 thou and bevelling the edges?
 
    You could use pencil leads for joining the graphite strips? Maybe plastic drinking straws? Then you would likely need much less Al or Cu for the damping plate?
 
    Regards,
 
    Chris
 

Subject: Question and Calibration Note From: "Geoff" gmvoeth@........... Date: Sat, 8 Dec 2007 20:15:55 -0700 Hello PSN; This is an offer to anyone on PSN who wants a Free Half-Life2 And/or Episode-1 game Just Send Me your email address and I will let Valve know to send these two extra FPS games. You must be over 17 since they are rated M. Contact me direct if anyone is interested. user name is gmvoeth address is hotmail(dot)com ***** CAL MARK TIMER BOARD NOTE ********* Im using a timer board to mix cal marks with the EQ data And have found it handy to use a hot glue gun to create trimmer caps for adjusting the oscillator. You take a length of 22Ga insulated wire strip off half the insulation then make an L bend about 1mm long then overlap the two wires 1mm sections then coat the overlap with the hot glue holding everything in place till it cools ( 15 min ? ) The oscillator must be first adjusted slightly fast maybe one second every two to four days then add trimmer caps like (one pico farad) 1pf or below directly across the crystal ( 12MHz ? ) till the timer is good for 48 hours or so. ( Estimated Within 0.1 seconds in 48 hours ) You should have a good cap meter to build these. You can not expect to get the exact freq. Regards; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fiji area quake From: "Thomas Dick" dickthomas01@............. Date: Sun, 9 Dec 2007 09:47:41 -0600 Is there anything wrong with the time or location for the 7.8 quake today? I'm not able to put the data into Winquake and get phases. I certaining register the quake in the time frame that it was suppose to arrive. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fiji area quake From: tchannel1@............ Date: Sun, 9 Dec 2007 10:41:55 -0700 Hi Dick, I did not have any problem, however I could not get all the phases like the LQ and LR, because I only copied about one hour of trace, so these did not show on my enlargement, just the earlier phases of course. Have you checked for type-o's on your event information? Ted ----- Original Message ----- From: "Thomas Dick" To: Sent: Sunday, December 09, 2007 8:47 AM Subject: Fiji area quake > Is there anything wrong with the time or location for the 7.8 quake today? > I'm not able to put the data into Winquake and get phases. I certaining > register the quake in the time frame that it was suppose to arrive. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fiji area quake From: Mark Robinson mark.robinson@............... Date: Mon, 10 Dec 2007 10:48:25 +1300 Thomas Dick wrote: > Is there anything wrong with the time or location for the 7.8 quake > today? I'm not able to put the data into Winquake and get phases. I > certaining register the quake in the time frame that it was suppose to > arrive. I felt that quake here at almost 1800km distance and can confirm the time. Looking at the traces I think it would be difficult to characterise the event as instantaneous. I was particularly struck by the huge very long period (~30min) waves shown on the Kermadec LISS seismograph shortly after the event (before they were obliterated by traces from subsequent hours). -- Mark __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fiji area quake From: "Thomas Dick" dickthomas01@............. Date: Sun, 9 Dec 2007 16:03:07 -0600 I don't think this is so simple. May be a quark in the software in reference to the location here in midwest -- too close to 180 degrees. There is no doubt that I got a good record. The arrival of Pdiff appears the same as on the local university helicorder and if I try to place Pdiff and S manually, I can get phases to come in (if I use the locate feature in conjunction) but if I move S one way or the other just a little everything disappears..I even processed a 2.4 locally about twenty minutes before with no trouble. So Larry's program works fine! ----- Original Message ----- From: "Mark Robinson" To: Sent: Sunday, December 09, 2007 3:48 PM Subject: Re: Fiji area quake > Thomas Dick wrote: >> Is there anything wrong with the time or location for the 7.8 quake >> today? I'm not able to put the data into Winquake and get phases. I >> certaining register the quake in the time frame that it was suppose to >> arrive. > > I felt that quake here at almost 1800km distance and can confirm the time. > > Looking at the traces I think it would be difficult to characterise the > event as instantaneous. > > I was particularly struck by the huge very long period (~30min) waves > shown on the Kermadec LISS seismograph shortly after the event (before > they were obliterated by traces from subsequent hours). > -- > Mark > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: > 269.16.17/1179 - Release Date: 12/9/2007 11:06 AM > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fiji area quake From: John Lahr johnjan@........ Date: Sun, 09 Dec 2007 14:51:56 -0800 Thomas, Check that you have the correct lat and lon for the Fiji event. It was not 180 degrees away from the mid west. For computed distances, see this USGS page: http://neic.usgs.gov/neis/eq_depot/2007/eq_071209_ksak/neic_ksak_t.html This page includes two seismograms from Oregon: http://jclahr.com/science/psn/as1/figi07/index.html Cheers, John At 02:03 PM 12/9/2007, you wrote: >I don't think this is so simple. May be a quark in the software in >reference to the location here in midwest -- too close to 180 >degrees. There is no doubt that I got a good record. The arrival of >Pdiff appears the same as on the local university helicorder and if >I try to place Pdiff and S manually, I can get phases to come in (if >I use the locate feature in conjunction) but if I move S one way or >the other just a little everything disappears..I even processed a >2.4 locally about twenty minutes before with no trouble. So Larry's >program works fine! >----- Original Message ----- From: "Mark Robinson" > >To: >Sent: Sunday, December 09, 2007 3:48 PM >Subject: Re: Fiji area quake > > >>Thomas Dick wrote: >>>Is there anything wrong with the time or location for the 7.8 >>>quake today? I'm not able to put the data into Winquake and get >>>phases. I certaining register the quake in the time frame that it >>>was suppose to arrive. >> >>I felt that quake here at almost 1800km distance and can confirm the time. >> >>Looking at the traces I think it would be difficult to characterise >>the event as instantaneous. >> >>I was particularly struck by the huge very long period (~30min) >>waves shown on the Kermadec LISS seismograph shortly after the >>event (before they were obliterated by traces from subsequent hours). >>-- >>Mark >>__________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email PSN-L-REQUEST@.............. with the body >>of the message (first line only): unsubscribe >>See http://www.seismicnet.com/maillist.html for more information. >> >> >>-- >>No virus found in this incoming message. >>Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: >>269.16.17/1179 - Release Date: 12/9/2007 11:06 AM >> >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with the body >of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fiji area quake From: "Thomas Dick" dickthomas01@............. Date: Sun, 9 Dec 2007 19:41:23 -0600 You're right John, I am NOT close to 180 degree from the epicenter. I have put the data in over ten times. Early on, I even reverse the 177 to a positive number to try and get it to show phases think it was an error on the post. The travel time table shows 107 degrees and 11896 km. I have made mistakes before...particularly before two cups of morning coffee but not this time. ----- Original Message ----- From: "John Lahr" To: Cc: "Thomas Dick" Sent: Sunday, December 09, 2007 4:51 PM Subject: Re: Fiji area quake > Thomas, > > Check that you have the correct lat and lon for the Fiji event. It was > not 180 degrees away from the mid west. > > For computed distances, see this USGS page: > http://neic.usgs.gov/neis/eq_depot/2007/eq_071209_ksak/neic_ksak_t.html > > This page includes two seismograms from Oregon: > http://jclahr.com/science/psn/as1/figi07/index.html > > Cheers, > John > At 02:03 PM 12/9/2007, you wrote: >>I don't think this is so simple. May be a quark in the software in >>reference to the location here in midwest -- too close to 180 degrees. >>There is no doubt that I got a good record. The arrival of Pdiff appears >>the same as on the local university helicorder and if I try to place Pdiff >>and S manually, I can get phases to come in (if I use the locate feature >>in conjunction) but if I move S one way or the other just a little >>everything disappears..I even processed a 2.4 locally about twenty minutes >>before with no trouble. So Larry's program works fine! >>----- Original Message ----- From: "Mark Robinson" >> >>To: >>Sent: Sunday, December 09, 2007 3:48 PM >>Subject: Re: Fiji area quake >> >> >>>Thomas Dick wrote: >>>>Is there anything wrong with the time or location for the 7.8 quake >>>>today? I'm not able to put the data into Winquake and get phases. I >>>>certaining register the quake in the time frame that it was suppose to >>>>arrive. >>> >>>I felt that quake here at almost 1800km distance and can confirm the >>>time. >>> >>>Looking at the traces I think it would be difficult to characterise the >>>event as instantaneous. >>> >>>I was particularly struck by the huge very long period (~30min) waves >>>shown on the Kermadec LISS seismograph shortly after the event (before >>>they were obliterated by traces from subsequent hours). >>>-- >>>Mark >>>__________________________________________________________ >>> >>>Public Seismic Network Mailing List (PSN-L) >>> >>>To leave this list email PSN-L-REQUEST@.............. with the body of >>>the message (first line only): unsubscribe >>>See http://www.seismicnet.com/maillist.html for more information. >>> >>> >>>-- >>>No virus found in this incoming message. >>>Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: >>>269.16.17/1179 - Release Date: 12/9/2007 11:06 AM >>> >>__________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email PSN-L-REQUEST@.............. with the body of the >>message (first line only): unsubscribe >>See http://www.seismicnet.com/maillist.html for more information. >> > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: > 269.16.17/1179 - Release Date: 12/9/2007 11:06 AM > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? From: "Geoff" gmvoeth@........... Date: Sun, 9 Dec 2007 19:07:39 -0700 I am thinking possibly an optical feedback system using a laser pointer or something to feedback positional data to an electromagnet you would use a PID loop of sorts like an auto speed controller to fix the position of the mass which is most likely a magnet hanging on a spring as the mass itself. You would get the signal somehow from the PID loop as it keeps the mass stationary like keeping an auto speed (MPH) steady. Just A thought sort of like those levitating globes but you would also have a spring as well as larger mass like 5 lb avdp or so instead of those lightweight globes. Regards; geoff ----- Original Message ----- From: "meredith lamb" To: Sent: Thursday, December 06, 2007 10:48 AM Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? > Hi Geoff, > > No, "I" haven't heard of such....however right off I can't think of "how" > one would do such > especially with only one coil in a geophone. Perhaps "if" you get away from > a geophone > and wander into say...a simple hanging spring with a mass on the bottom, > then it might > be more interesting (relatively unknown territory) as you might be able to > add stuff, and go from there. > My nephew David has used a hanging directional (horizontal) "S-G", with a > natural period of ~ 1.5s > and "added" acouple magnets; one to the bottom of the mass, and a much > larger flat one below > that. The magnets are arranged to be repelling; i.e., with the same pole > facing each other. > If you carefully adjust the larger magnet it will extend the natural period > of the S-G somewhat. > David claimed he got up to a reliable 8 second natural period; but it > involved precisely setting the > positions of the magnets. David claims he got up to 11 seconds; but that > was alot less stable. > He "settled" on using samarium magnets for his model, as the temperature > results with > neodymium magnets was less suitable. > > I roughly tried it myself with the table top directional hanging horizontal > model I have with > the cross rod magnets pivot...about 10 days ago. I only used a box on the > floor to put the > larger magnet on and position it directly underneath the small magnet on the > bottom of the > mass.....it was easy to get a extended 3 second period initially. Visually > it "appeared" that > the undampened free oscillation swinging motion was reasonably harmonic. > > I suppose there is likely a problem or problems with doing such...I've not > really thought about > it since the brief trial. If one uses a coil and other magnets on > such...then things get hairy > with perhaps the potential of magnetic interaction potential > problems...especially if the > distances between the magnets is too close. > > How the above could apply to your initial question; in regard to a hanging > spring and mass > or what results you might see are unknown. > > I suppose one could also try such with about any vertical just to explore > what happens? > I would think the magnets "might" have to be, directly in front of the mass > for a "traditional" > vertical layout; rather than underneath.... > > I think Sprengnether company initially tried one or more magnetic > seismometers way back > in time. But I know nothing of their results. > > Good unknown questions, with no immediate answers....this is the kind of > chewy stuff > that makes for some fun trials.... > > Take care, Meredith > On Dec 5, 2007 8:41 PM, Geoff wrote: > >> Hello PSN Folks; >> >> Has anyone ever used a spring >> to take up most the mass weight then >> maybe apply an ounce or less levitation >> magnetically to set with electronics >> the free period within a geophone. >> >> Id think you would pump a current limited signal >> into the geophone and use some kind of >> feedback circuit that might set >> the free period. I am looking only >> for a free period in the 3 to 4 second >> range. >> >> If you take up the small weight with your hand >> it seems you can move the hand up and down >> at whatever period and the system will >> not oppose what you are doing ?? >> >> Comments welcome. >> >> Regards >> geoff >> __________________________________________________________ >> > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fiji area quake From: Mark Robinson mark.robinson@............... Date: Mon, 10 Dec 2007 15:30:07 +1300 Thomas Dick wrote: > You're right John, I am NOT close to 180 degree from the epicenter. I > have put the data in over ten times. Early on, I even reverse the 177 to > a positive number to try and get it to show phases think it was an error > on the post. The travel time table shows 107 degrees and 11896 km. I > have made mistakes before...particularly before two cups of morning > coffee but not this time. "The shadow zone is the area of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves." http://earthquake.usgs.gov/learning/glossary.php?termID=170&alpha=S > ----- Original Message ----- From: "John Lahr" >> Check that you have the correct lat and lon for the Fiji event. It >> was not 180 degrees away from the mid west. >> For computed distances, see this USGS page: >> http://neic.usgs.gov/neis/eq_depot/2007/eq_071209_ksak/neic_ksak_t.html >> This page includes two seismograms from Oregon: >> http://jclahr.com/science/psn/as1/figi07/index.html >> At 02:03 PM 12/9/2007, you wrote: >>> I don't think this is so simple. May be a quark in the software in >>> reference to the location here in midwest -- too close to 180 >>> degrees. There is no doubt that I got a good record. The arrival of >>> Pdiff appears the same as on the local university helicorder and if I >>> try to place Pdiff and S manually, I can get phases to come in (if I >>> use the locate feature in conjunction) but if I move S one way or >>> the other just a little everything disappears..I even processed a 2.4 >>> locally about twenty minutes before with no trouble. So Larry's >>> program works fine! >>> ----- Original Message ----- From: "Mark Robinson" >>> >>> To: >>> Sent: Sunday, December 09, 2007 3:48 PM >>> Subject: Re: Fiji area quake >>> >>> >>>> Thomas Dick wrote: >>>>> Is there anything wrong with the time or location for the 7.8 quake >>>>> today? I'm not able to put the data into Winquake and get phases. I >>>>> certaining register the quake in the time frame that it was suppose >>>>> to arrive. >>>> >>>> I felt that quake here at almost 1800km distance and can confirm the >>>> time. >>>> >>>> Looking at the traces I think it would be difficult to characterise >>>> the event as instantaneous. >>>> >>>> I was particularly struck by the huge very long period (~30min) >>>> waves shown on the Kermadec LISS seismograph shortly after the event >>>> (before they were obliterated by traces from subsequent hours). -- Mark Robinson ------------- 10 Dec 1953 Winston Churchill wins Nobel prize for literature. 10 Dec 1965 Annie Crummer born. 10 Dec 1972 Split Enz play their debut at Auckland Wynyard Tavern. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Combination spring-mag_levitation Anyone Tried This ?? From: ChrisAtUpw@....... Date: Sun, 9 Dec 2007 22:40:06 EST In a message dated 10/12/2007, gmvoeth@........... writes: I am thinking possibly an optical feedback system using a laser pointer or something to feedback positional data to an electromagnet Hi Geoff, Filament bulbs are fine as light sources for Si photodiodes. Lasers are hideously noisy. LEDs tend to be noisy with the exceptions of the superbright and the IR ones. The light output varies by x5 for the same current between 0 and 100 C. You need to stabilise the output. Regards, Chris Chapman
In a message dated 10/12/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am=20 thinking possibly an optical feedback system using a laser pointer or=20 something
to feedback positional data to an=20 electromagnet
Hi Geoff,
 
    Filament bulbs are fine as light sources for Si= =20 photodiodes. Lasers are hideously noisy. LEDs tend to be noisy with the=20 exceptions of the superbright and the IR ones. The light output varies by x5= for=20 the same current between 0 and 100 C. You need to stabilise the=20 output.
 
    Regards,
 
    Chris Chapman
 
    
Subject: Figi event From: "Thomas Dick" dickthomas01@............. Date: Mon, 10 Dec 2007 05:33:52 -0600 Thanks John and Bob. I have started from the beginning at least five = times and save within WinQuake dozens of times now. I have made mistakes = before so I didn't admit this problem quickly.I got good results on this = quake. I have put the numbers in maybe fifty times. It doesn't matter. = Using the data below and resetting P and S manually within Winquake I = can get phases to appear but only if I am very close to actual Pdiff and = S arrival times. If I am off even a little (checked using locate) all = phases disappear and I can't save. ----- Original Message -----=20 From: Bobhelenmcclure@.......... To: dickthomas01@................ Sent: Sunday, December 09, 2007 10:25 PM Subject: Travel Times for Figi event Here is what my travel time program gave for your location. Station: 38.001 -87.5146 Event:-25.872 -177.517 Depth 149.2 km EventTime 07:28:21 11716.81 Km Delta 105.43 (deg) Azimuth 249.1673 (deg, station to event) Azimuth 55.0416 (deg, event to station) travel arrival ground time time velocity Pdif 833.6 07:42:14.6 24.701 PP 1099.5 07:46:40.5 15.089 PPP 1228.1 07:48:49.1 12.939 SKP(df) 1284.6 07:49:45.6 56.918 PKS(df) 1299.9 07:50:00.9 56.821 pPKS(df) 1359.6 07:51:00.6 56.82 sPKS(df) 1390.2 07:51:31.2 56.624 SKS(ac) 1457.7 07:52:38.7 24.977 SKS(df) 1500.7 07:53:21.7 57.314 sSKS(ac) 1562.0 07:54:23.0 24.749 sSKS(df) 1605.8 07:55:06.8 56.827 SP 1633.1 07:55:34.1 11.155 PS 1650.8 07:55:51.8 11.283 SPP 1687.1 07:56:28.1 9.286 PPS 1707.5 07:56:48.5 9.41 PKKP(bc) 1769.2 07:57:50.2 -39.471 PKKP(df) 1778.3 07:57:59.3 -61.811 PKKP(ab) 1789.6 07:58:10.6 -25.079 pPKKP(bc) 1828.3 07:58:49.3 -38.804 pPKKP(df) 1838.0 07:58:59.0 -61.811 pPKKP(ab) 1847.0 07:59:08.0 -25.05 sPKKP(bc) 1859.2 07:59:20.2 -39.024 sPKKP(df) 1868.6 07:59:29.6 -61.811 sPKKP(ab) 1878.3 07:59:39.3 -25.065 SS 1981.8 08:01:22.8 8.165 SSS 2222.8 08:05:23.8 7.214 PKPPKP(df) 2273.3 08:06:14.3 -59.221 ************************************** Check out AOL's list of 2007's hottest products. = (http://money.aol.com/special/hot-products-2007?NCID=3Daoltop000300000000= 01)=20 -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Free Edition.=20 Version: 7.5.503 / Virus Database: 269.16.17/1179 - Release Date: = 12/9/2007 11:06 AM
Thanks John and Bob. I have started = from the=20 beginning at least five times and save within WinQuake dozens of = times now.=20 I have made mistakes before so I didn't admit this problem quickly.I got = good=20 results on this quake. I have put the numbers in maybe fifty times. = It=20 doesn't matter. Using the data below and resetting P and S manually = within=20 Winquake I can get phases to appear but only if I am very close to = actual Pdiff=20 and S arrival times. If I am off even a little (checked using locate) = all phases=20 disappear and I can't save.
----- Original Message -----
From:=20 Bobhelenmcclure@....... =
Sent: Sunday, December 09, 2007 = 10:25=20 PM
Subject: Travel Times for Figi=20 event

Here is what my travel time = program gave for=20 your location.

Station: 38.001 -87.5146
  Event:-25.872 = -177.517
Depth 149.2 km
EventTime 07:28:21
11716.81 = Km
Delta =20 105.43 (deg)
Azimuth  249.1673 (deg, station to=20 event)
Azimuth  55.0416 (deg, event to=20 = station)

         &nb= sp; =20 travel   arrival     =20 = ground
          &nb= sp;=20 time    =20 time        =20 velocity
Pdif        =20 833.6   07:42:14.6  =20 24.701
PP         =20 1099.5   07:46:40.5  =20 15.089
PPP        =20 1228.1   07:48:49.1  =20 12.939
SKP(df)     1284.6  =20 07:49:45.6   56.918
PKS(df)    =20 1299.9   07:50:00.9   = 56.821
pPKS(df)   =20 1359.6   07:51:00.6   = 56.82
sPKS(df)   =20 1390.2   07:51:31.2  =20 56.624
SKS(ac)     1457.7  =20 07:52:38.7   24.977
SKS(df)    =20 1500.7   07:53:21.7   = 57.314
sSKS(ac)   =20 1562.0   07:54:23.0   = 24.749
sSKS(df)   =20 1605.8   07:55:06.8  =20 56.827
SP         =20 1633.1   07:55:34.1  =20 11.155
PS         =20 1650.8   07:55:51.8  =20 11.283
SPP        =20 1687.1   07:56:28.1  =20 9.286
PPS        =20 1707.5   07:56:48.5   = 9.41
PKKP(bc)   =20 1769.2   07:57:50.2  = -39.471
PKKP(df)   =20 1778.3   07:57:59.3  = -61.811
PKKP(ab)   =20 1789.6   07:58:10.6  -25.079
pPKKP(bc)  =20 1828.3   07:58:49.3  -38.804
pPKKP(df)  =20 1838.0   07:58:59.0  -61.811
pPKKP(ab)  =20 1847.0   07:59:08.0  -25.05
sPKKP(bc)  =20 1859.2   07:59:20.2  -39.024
sPKKP(df)  =20 1868.6   07:59:29.6  -61.811
sPKKP(ab)  =20 1878.3   07:59:39.3 =20 -25.065
SS         =20 1981.8   08:01:22.8  =20 8.165
SSS        =20 2222.8   08:05:23.8   7.214
PKPPKP(df) =20 2273.3   08:06:14.3 =20 = -59.221



**************************************
C= heck=20 out AOL's list of 2007's hottest=20 = products.
(http://money.aol.com/special/hot-products-2007?NCID=3Daolto= p00030000000001)=20

No virus found in this incoming message.
Checked by AVG Free = Edition.
Version: 7.5.503 / Virus Database: 269.16.17/1179 - = Release Date:=20 12/9/2007 11:06 AM
 Subject: Re: Figi event From: Mark Robinson mark.robinson@............... Date: Tue, 11 Dec 2007 09:40:12 +1300 Thomas Dick wrote: > Thanks John and Bob. I have started from the beginning at least five > times and save within WinQuake dozens of times now. I have made mistakes > before so I didn't admit this problem quickly.I got good results on this > quake. I have put the numbers in maybe fifty times. It doesn't matter. > Using the data below and resetting P and S manually within Winquake I > can get phases to appear but only if I am very close to actual Pdiff and > S arrival times. If I am off even a little (checked using locate) all > phases disappear and I can't save. > > ----- Original Message ----- > *From:* Bobhelenmcclure@....... > *To:* dickthomas01@............. > *Sent:* Sunday, December 09, 2007 10:25 PM > *Subject:* Travel Times for Figi event > > Here is what my travel time program gave for your location. > > Station: 38.001 -87.5146 > Event:-25.872 -177.517 > Depth 149.2 km > EventTime 07:28:21 > 11716.81 Km > Delta 105.43 (deg) > Azimuth 249.1673 (deg, station to event) > Azimuth 55.0416 (deg, event to station) > > travel arrival ground > time time velocity > Pdif 833.6 07:42:14.6 24.701 > PP 1099.5 07:46:40.5 15.089 > PPP 1228.1 07:48:49.1 12.939 > SKP(df) 1284.6 07:49:45.6 56.918 > PKS(df) 1299.9 07:50:00.9 56.821 > pPKS(df) 1359.6 07:51:00.6 56.82 > sPKS(df) 1390.2 07:51:31.2 56.624 > SKS(ac) 1457.7 07:52:38.7 24.977 > SKS(df) 1500.7 07:53:21.7 57.314 > sSKS(ac) 1562.0 07:54:23.0 24.749 > sSKS(df) 1605.8 07:55:06.8 56.827 > SP 1633.1 07:55:34.1 11.155 > PS 1650.8 07:55:51.8 11.283 > SPP 1687.1 07:56:28.1 9.286 > PPS 1707.5 07:56:48.5 9.41 > PKKP(bc) 1769.2 07:57:50.2 -39.471 > PKKP(df) 1778.3 07:57:59.3 -61.811 > PKKP(ab) 1789.6 07:58:10.6 -25.079 > pPKKP(bc) 1828.3 07:58:49.3 -38.804 > pPKKP(df) 1838.0 07:58:59.0 -61.811 > pPKKP(ab) 1847.0 07:59:08.0 -25.05 > sPKKP(bc) 1859.2 07:59:20.2 -39.024 > sPKKP(df) 1868.6 07:59:29.6 -61.811 > sPKKP(ab) 1878.3 07:59:39.3 -25.065 > SS 1981.8 08:01:22.8 8.165 > SSS 2222.8 08:05:23.8 7.214 > PKPPKP(df) 2273.3 08:06:14.3 -59.221 There's another page on the USGS site which shows the shadow effect in operation for this quake for stations in the USA by plotting traces by distance in degrees: http://neic.usgs.gov/neis/eq_depot/2007/eq_071209_ksak/neic_ksak_r.html I suspect that the considerable attenuation is causing WinQuake's phase picking some grief. -- Mark Robinson ------------- 11 Dec 1951 Yankee slugger Joe DiMaggio announces his retirement from baseball. 11 Dec 1991 EEC aggrees to political federation and common currency by 1999. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Phases From: "Randy" rpratt@............. Date: Mon, 10 Dec 2007 17:40:56 -0600 Tom, I am having the same problem with phases. I have seen it occasionally = in the past but never figured it out. Look at my screen shot at = http://mit.midco.net/rpratt/ I can not move the S and get other = phases. =20 Randy
Tom,
 
I am having the same problem with = phases.  I=20 have seen it occasionally in the past but never figured it out.  = Look at my=20 screen shot at http://mit.midco.net/rpratt/&nb= sp; =20 I can not move the S and get other phases.  
 
Randy
Subject: Re: Phases From: tchannel1@............ Date: Mon, 10 Dec 2007 16:52:29 -0700 Hi Randy, I too am having the same problem. I thought it was my = software so I uninstalled and reinstalled, this did not help. Is yours = only if you change the p and s? I do this, in order to make a time = adjustment, like add 5 seconds, because my computer clock is off. I do = not know if it errors, if I don't change my time.....I could try this on = my next event, that is fill all the event information, then try to place = my phases..........and if its all okay, then make my time adjustment and = try the phases again. Thanks, Ted ----- Original Message -----=20 From: Randy=20 To: psn-l@................. Sent: Monday, December 10, 2007 4:40 PM Subject: Phases Tom, I am having the same problem with phases. I have seen it occasionally = in the past but never figured it out. Look at my screen shot at = http://mit.midco.net/rpratt/ I can not move the S and get other = phases. =20 Randy
Hi Randy,  I too am having the = same=20 problem.  I thought it was my software so I uninstalled and = reinstalled,=20 this did not help.  Is yours only if you change the p and s?  = I do=20 this, in order to make a time adjustment, like add 5 seconds, because my = computer clock is off.   I do not know if it errors, if I = don't change=20 my time.....I could try this on my next event, that is fill all the = event=20 information, then try to place my phases..........and if its all okay, = then make=20 my time adjustment and try the phases again.
 
Thanks, Ted
----- Original Message -----
From:=20 Randy=20
Sent: Monday, December 10, 2007 = 4:40=20 PM
Subject: Phases

Tom,
 
I am having the same problem with = phases.  I=20 have seen it occasionally in the past but never figured it out.  = Look at=20 my screen shot at http://mit.midco.net/rpratt/&nb= sp; =20 I can not move the S and get other phases.  
 
Randy
Subject: Re: Figi event From: Stephen & Kathy skmort@............ Date: Mon, 10 Dec 2007 16:53:55 -0800 FYI,, the phases seem to be related to depth?? At least for me at about 83 degrees, if I set the depth greater than 100, LR and LQ are not shown, at 100 or less they are! Stephen PSN Station #55 Mark Robinson wrote: > Thomas Dick wrote: >> Thanks John and Bob. I have started from the beginning at least five >> times and save within WinQuake dozens of times now. I have made >> mistakes before so I didn't admit this problem quickly.I got good >> results on this quake. I have put the numbers in maybe fifty times. >> It doesn't matter. Using the data below and resetting P and S >> manually within Winquake I can get phases to appear but only if I am >> very close to actual Pdiff and S arrival times. If I am off even a >> little (checked using locate) all phases disappear and I can't save. >> >> ----- Original Message ----- >> *From:* Bobhelenmcclure@....... >> *To:* dickthomas01@............. >> *Sent:* Sunday, December 09, 2007 10:25 PM >> *Subject:* Travel Times for Figi event >> >> Here is what my travel time program gave for your location. >> >> Station: 38.001 -87.5146 >> Event:-25.872 -177.517 >> Depth 149.2 km >> EventTime 07:28:21 >> 11716.81 Km >> Delta 105.43 (deg) >> Azimuth 249.1673 (deg, station to event) >> Azimuth 55.0416 (deg, event to station) >> >> travel arrival ground >> time time velocity >> Pdif 833.6 07:42:14.6 24.701 >> PP 1099.5 07:46:40.5 15.089 >> PPP 1228.1 07:48:49.1 12.939 >> SKP(df) 1284.6 07:49:45.6 56.918 >> PKS(df) 1299.9 07:50:00.9 56.821 >> pPKS(df) 1359.6 07:51:00.6 56.82 >> sPKS(df) 1390.2 07:51:31.2 56.624 >> SKS(ac) 1457.7 07:52:38.7 24.977 >> SKS(df) 1500.7 07:53:21.7 57.314 >> sSKS(ac) 1562.0 07:54:23.0 24.749 >> sSKS(df) 1605.8 07:55:06.8 56.827 >> SP 1633.1 07:55:34.1 11.155 >> PS 1650.8 07:55:51.8 11.283 >> SPP 1687.1 07:56:28.1 9.286 >> PPS 1707.5 07:56:48.5 9.41 >> PKKP(bc) 1769.2 07:57:50.2 -39.471 >> PKKP(df) 1778.3 07:57:59.3 -61.811 >> PKKP(ab) 1789.6 07:58:10.6 -25.079 >> pPKKP(bc) 1828.3 07:58:49.3 -38.804 >> pPKKP(df) 1838.0 07:58:59.0 -61.811 >> pPKKP(ab) 1847.0 07:59:08.0 -25.05 >> sPKKP(bc) 1859.2 07:59:20.2 -39.024 >> sPKKP(df) 1868.6 07:59:29.6 -61.811 >> sPKKP(ab) 1878.3 07:59:39.3 -25.065 >> SS 1981.8 08:01:22.8 8.165 >> SSS 2222.8 08:05:23.8 7.214 >> PKPPKP(df) 2273.3 08:06:14.3 -59.221 > > There's another page on the USGS site which shows the shadow effect in > operation for this quake for stations in the USA by plotting traces by > distance in degrees: > > > http://neic.usgs.gov/neis/eq_depot/2007/eq_071209_ksak/neic_ksak_r.html > > I suspect that the considerable attenuation is causing WinQuake's > phase picking some grief. FYI,,  the phases seem to be related to depth??  At least for me at about 83 degrees, if I set the depth greater than 100, LR and LQ are not shown, at 100 or less they are!
  Stephen
  PSN Station #55

Mark Robinson wrote:
Thomas Dick wrote:
Thanks John and Bob. I have started from the beginning at least five times and save within WinQuake dozens of times now. I have made mistakes before so I didn't admit this problem quickly.I got good results on this quake. I have put the numbers in maybe fifty times. It doesn't matter. Using the data below and resetting P and S manually within Winquake I can get phases to appear but only if I am very close to actual Pdiff and S arrival times. If I am off even a little (checked using locate) all phases disappear and I can't save.

    ----- Original Message -----
    *From:* Bobhelenmcclure@....... <mailto:Bobhelenmcclure@.......>
    *To:* dickthomas01@............. <mailto:dickthomas01@.............>
    *Sent:* Sunday, December 09, 2007 10:25 PM
    *Subject:* Travel Times for Figi event

    Here is what my travel time program gave for your location.

    Station: 38.001 -87.5146
      Event:-25.872 -177.517
    Depth 149.2 km
    EventTime 07:28:21
    11716.81 Km
    Delta  105.43 (deg)
    Azimuth  249.1673 (deg, station to event)
    Azimuth  55.0416 (deg, event to station)

                travel   arrival      ground
                time     time         velocity
    Pdif         833.6   07:42:14.6   24.701
    PP          1099.5   07:46:40.5   15.089
    PPP         1228.1   07:48:49.1   12.939
    SKP(df)     1284.6   07:49:45.6   56.918
    PKS(df)     1299.9   07:50:00.9   56.821
    pPKS(df)    1359.6   07:51:00.6   56.82
    sPKS(df)    1390.2   07:51:31.2   56.624
    SKS(ac)     1457.7   07:52:38.7   24.977
    SKS(df)     1500.7   07:53:21.7   57.314
    sSKS(ac)    1562.0   07:54:23.0   24.749
    sSKS(df)    1605.8   07:55:06.8   56.827
    SP          1633.1   07:55:34.1   11.155
    PS          1650.8   07:55:51.8   11.283
    SPP         1687.1   07:56:28.1   9.286
    PPS         1707.5   07:56:48.5   9.41
    PKKP(bc)    1769.2   07:57:50.2  -39.471
    PKKP(df)    1778.3   07:57:59.3  -61.811
    PKKP(ab)    1789.6   07:58:10.6  -25.079
    pPKKP(bc)   1828.3   07:58:49.3  -38.804
    pPKKP(df)   1838.0   07:58:59.0  -61.811
    pPKKP(ab)   1847.0   07:59:08.0  -25.05
    sPKKP(bc)   1859.2   07:59:20.2  -39.024
    sPKKP(df)   1868.6   07:59:29.6  -61.811
    sPKKP(ab)   1878.3   07:59:39.3  -25.065
    SS          1981.8   08:01:22.8   8.165
    SSS         2222.8   08:05:23.8   7.214
    PKPPKP(df)  2273.3   08:06:14.3  -59.221

There's another page on the USGS site which shows the shadow effect in operation for this quake for stations in the USA by plotting traces by distance in degrees:

    http://neic.usgs.gov/neis/eq_depot/2007/eq_071209_ksak/neic_ksak_r.html

I suspect that the considerable attenuation is causing WinQuake's phase picking some grief.
Subject: Re: Phases OK <<<<<<<<<<< From: "Jim ODonnell" geophysics@.......... Date: Tue, 11 Dec 2007 03:27:14 GMT Randy & others- Deep earthquakes do not generarte Rayleigh waves. Rayleigh is generated from a P & Sv reflecting off the earth air interfa= ce- which is an excellent reflector- They combine together to form Rayl= eigh- See: Surface Waves: Rayleigh & Love http://www.uwm.edu/~bketter/Researc= h/Surface_Theory/Surface.html Jim Jim O'Donnell = Geological/Geophysical Consultant GEOTECHNICAL APPLICATIONS 702.293.5664 geophysics@.......... 702.281.9081 cell jimo17@........ -- wrote: Hi Randy, I too am having the same problem. I thought it was my softwa= re so I uninstalled and reinstalled, this did not help. Is yours only i= f you change the p and s? I do this, in order to make a time adjustment= , like add 5 seconds, because my computer clock is off. I do not know = if it errors, if I don't change my time.....I could try this on my next = event, that is fill all the event information, then try to place my phas= es..........and if its all okay, then make my time adjustment and try th= e phases again. Thanks, Ted----- Original Message ----- From: Randy To: = psn-l@.............. Sent: Monday, December 10, 2007 4:40 PMSubject: Pha= ses Tom, I am having the same problem with phases. I have seen it occasiona= lly in the past but never figured it out. Look at my screen shot at htt= p://mit.midco.net/rpratt/ I can not move the S and get other phases. = Randy

Randy & others-
Deep earthquakes do not generart= e Rayleigh waves.
Rayleigh is generated from a P & Sv re= flecting off the earth air interface- which is an excellent reflector-&n= bsp; They combine together to form Rayleigh-
See: Surface Waves: Rayleigh & Love  http://www.uwm.edu/~bketter/Research/= Surface_Theory/Surface.html

Jim

 =             =      Jim O'Donnell     
=         Geological/Geophysical C= onsultant
          = ; GEOTECHNICAL APPLICATIONS
702.293.5664    geoph= ysics@..........
702.281.9081 cell   jimo17@........
-- <tchannel1@............> wrote:

Hi Randy,  I too am having the sam= e problem.  I thought it was my software so I uninstalled and reins= talled, this did not help.  Is yours only if you change the p and s= ?  I do this, in order to make a time adjustment, like add 5 second= s, because my computer clock is off.   I do not know if it err= ors, if I don't change my time.....I could try this on my next event, th= at is fill all the event information, then try to place my phases.......= ....and if its all okay, then make my time adjustment and try the phases = again.
 
Thanks, Ted
----- Original Message -----
= From: Randy
Sent: Monday, December 10, 2007 4= :40 PM
Subject: Phases

Tom,
 
I am having the same problem with phase= s.  I have seen it occasionally in the past but never figured it ou= t.  Look at my screen shot at http://mit.midco.net/rpratt/   I can not move the S an= d get other phases.  
 
Randy
Subject: Re: Figi event From: Bobhelenmcclure@....... Date: Mon, 10 Dec 2007 22:34:48 EST Hi all, WinQuake does not allow phase picking for distances greater than about 100 degrees, which is the limit for P waves. However, if you enter the event coordinates and time, you will be able to see phases OK. Bob ************************************** See AOL's top rated recipes (http://food.aol.com/top-rated-recipes?NCID=aoltop00030000000004) Hi all,

  WinQuake does not allow phase picking for distances greater than abou= t 100 degrees, which is the limit for P waves. However, if you enter the eve= nt coordinates and time, you will be able to see phases OK.

Bob


**************************************
See AOL's to= p rated recipes (http://food.aol.com/top-rated-recipes?NCID=3Daoltop00030000= 000004) Subject: Phases From: "Randy" rpratt@............. Date: Tue, 11 Dec 2007 13:04:23 -0600 Thanks Jim, Good to get the expert answer from you. =20 PS - It's that time of year I wouldn't mind being back in your = neighborhood for a few months of seismogram training again but I would = miss my hockey. =20 Randy
Thanks Jim,
 
Good to get the expert answer from = you. =20
 
PS - It's that time of year I wouldn't = mind being=20 back in your neighborhood for a few months of seismogram = training again but=20 I would miss my hockey. 
 
Randy
Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Wed, 12 Dec 2007 16:49:57 -0700 Hi Chris, I've tried both your ideas of copper sheet and pencil leads, in a different (unintentional) diamagnetic levitation variation model and thus far the results have been noteably quite useful. The web page reference below was initially meant to cover just one topic of simply seeing what happens when the plastic spacers between the magnets is thicker....but it rapidly escalated from there..... http://diamagnetics.googlepages.com/magnetspace Take care, Meredith On Dec 8, 2007 7:51 AM, wrote: > In a message dated 08/12/2007, paleoartifact@......... writes: > > Hi Meredith, > > > You could use pencil leads for joining the graphite strips? Maybe > plastic drinking straws? Then you would likely need much less Al or Cu for > the damping plate? > > Regards, > > Chris > >
Hi Chris,
 
I've tried both your ideas of copper sheet and pencil leads, in a different (unintentional) diamagnetic
levitation variation model and thus far the results have been noteably quite useful.  The web page
reference below was initially meant to cover just one topic of simply seeing what happens when the
plastic spacers between the magnets is thicker....but it rapidly escalated from there.....
 
 
Take care, Meredith 

On Dec 8, 2007 7:51 AM, <ChrisAtUpw@.......> wrote:
In a message dated 08/12/2007, paleoartifact@......... writes:
Hi Meredith,
      
    You could use pencil leads for joining the graphite strips? Maybe plastic drinking straws? Then you would likely need much less Al or Cu for the damping plate?
 
    Regards,
 
    Chris
 

Subject: Re: General Diamagnetic Tiltmeter Improvements From: ChrisAtUpw@....... Date: Wed, 12 Dec 2007 19:35:24 EST In a message dated 12/12/2007, paleoartifact@......... writes: I've tried both your ideas of copper sheet and pencil leads, in a different (unintentional) diamagnetic levitation variation model and thus far the results have been noteably quite useful. Hi Meredith, I have also used D shaped pencil leads. I stick some say 32 thou sheet onto a flat backing plate with double sided tape, apply the round lead to the L edge of the plate and then sand off the top with new emery paper on a flat backing plate. You can 'roll' the lead carefully off the sticky tape when you have finished sanding. If you have any problems, heat from a hair drier can help a lot. You would likely get quite strong damping if you made the Cu end foils wider so that they overlapped the end magnet + 1/2 the outside magnets? The field gradients should be considerable here? Have you suffered from freezing rain in Denver? There have been some very catastrophic looking pictures on TV. The last time we had this problem was back in the 1940s. The two part acrylic glue is very good for sticking carbon. Devweld 530 should be available to you in twin tubes? I use Holdtite 3295. Hope that you are all well! Regards, Chris
In a message dated 12/12/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I've tried both your ideas of copper sheet and pencil leads, in a=20 different (unintentional) diamagnetic
levitation variation model and thus far the results have been noteabl= y=20 quite useful. 
Hi Meredith,
 
    I have also used D shaped pencil leads. I stick= =20 some say 32 thou sheet onto a flat backing plate with double sided tape, app= ly=20 the round lead to the L edge of the plate and then sand off the top with new= =20 emery paper on a flat backing plate. You can 'roll' the lead carefully=20= off=20 the sticky tape when you have finished sanding. If you have any problems, he= at=20 from a hair drier can help a lot. 
 
    You would likely get quite strong damping if yo= u=20 made the Cu end foils wider so that they overlapped the end magnet + 1/2 the= =20 outside magnets?  The field gradients should be considerable=20 here?
 
    Have you suffered from freezing rain in Denver?= =20 There have been some very catastrophic looking pictures on TV. The last= =20 time we had this problem was back in the 1940s. 
 
    The two part acrylic glue is very good for= =20 sticking carbon. Devweld 530 should be available to you in twin tubes? I use= =20 Holdtite 3295.
 
    Hope that you are all well!
 
    Regards,
 
    Chris
 
 Subject: Unknown event From: tchannel1@............ Date: Thu, 13 Dec 2007 09:09:17 -0700 Hi Folks, At about 10:52 utc we recorded and unknown..........at least = I do not see it published anywhere yet. Do you know? Thanks, Ted
Hi Folks,   At about 10:52 = utc we=20 recorded and unknown..........at least I do not see it published = anywhere=20 yet.
Do you know?
 
Thanks, Ted
Subject: Re: Unknown event From: "Jerry Payton" gpayton880@....... Date: Thu, 13 Dec 2007 10:14:35 -0600 MAG UTC DATE-TIME y/m/d h:m:s LAT deg LON deg DEPTH km Region MAP 6.2 2007/12/13 15:51:32 -15.175 -172.496 45.0 SAMOA ISLANDS REGION ----- Original Message ----- From: tchannel1@............ To: psn Sent: Thursday, December 13, 2007 10:09 AM Subject: Unknown event Hi Folks, At about 10:52 utc we recorded and unknown..........at least I do not see it published anywhere yet. Do you know? Thanks, Ted
  MAG UTC DATE-TIME
y/m/d = h:m:s=20 		LAT
deg 		LON
deg 		DEPTH
km 		 Region
MAP  6.2=20   2007/12/13 15:51:32   -15.175   -172.496  45.0   SAMOA ISLANDS=20 REGION
 
 
----- Original Message -----=20
From: tchannel1@............
To: psn
Sent: Thursday, December 13, 2007 10:09 AM
Subject: Unknown event

Hi Folks,   At about 10:52 = utc we=20 recorded and unknown..........at least I do not see it published = anywhere=20 yet.
Do you know?
 
Thanks, Ted
Subject: Re: Unknown event From: "Jerry Payton" gpayton880@....... Date: Thu, 13 Dec 2007 10:23:25 -0600 Oooops! Sorry Ted & All, I didn't notice your "utc" notation and posted my last, which was NOT correct. Ted, I check the European site and nothing posted there either for that time frame. Jerry ----- Original Message ----- From: tchannel1@............ To: psn Sent: Thursday, December 13, 2007 10:09 AM Subject: Unknown event Hi Folks, At about 10:52 utc we recorded and unknown..........at least I do not see it published anywhere yet. Do you know? Thanks, Ted
Oooops!  Sorry Ted & All,
 
I didn't notice your "utc" notation and posted my last, which was = NOT=20 correct.  Ted, I check the European site and nothing posted there = either=20 for that time frame.
Jerry
 
 
----- Original Message -----=20
From: tchannel1@............
To: psn
Sent: Thursday, December 13, 2007 10:09 AM
Subject: Unknown event

Hi Folks,   At about 10:52 = utc we=20 recorded and unknown..........at least I do not see it published = anywhere=20 yet.
Do you know?
 
Thanks, Ted
Subject: Re: Unknown event From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 13 Dec 2007 16:50:05 +0000 Hi Is it possible that you did recored a regonal earthquake ? Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Unknown event From: tchannel1@............ Date: Thu, 13 Dec 2007 09:59:59 -0700 I looked at other Idaho and Montana helicorders and they recorded it at the same time. It might be regional, but (as of now) I don't see it listed anywhere. Just guessing it must be greater than a M3, also guessing around 1000 miles or closer? Thanks, Ted . ----- Original Message ----- From: "Jón Frímann" To: Sent: Thursday, December 13, 2007 9:50 AM Subject: Re: Unknown event Hi Is it possible that you did recored a regonal earthquake ? Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Unknown event From: "Jerry Payton" gpayton880@....... Date: Thu, 13 Dec 2007 11:17:46 -0600 This one in Wyoming show something about that time, but many others in adjacent states do not. Must be local. http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.MCID_EHZ_WY.2007121300.gif Jerry ----- Original Message ----- From: tchannel1@............ To: psn-l@.............. Sent: Thursday, December 13, 2007 10:59 AM Subject: Re: Unknown event I looked at other Idaho and Montana helicorders and they recorded it at the same time. It might be regional, but (as of now) I don't see it listed anywhere. Just guessing it must be greater than a M3, also guessing around 1000 miles or closer? Thanks, Ted . ----- Original Message ----- From: "Jón Frímann" To: Sent: Thursday, December 13, 2007 9:50 AM Subject: Re: Unknown event Hi Is it possible that you did recored a regonal earthquake ? Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
This one in Wyoming show something about that time, but many others = in=20 adjacent states do not.  Must be local.
http://www.seis.utah.edu/helicorder/heli/yellowstone= /Uuss.MCID_EHZ_WY.2007121300.gif
 
Jerry
 
 
----- Original Message -----=20
From: tchannel1@............
Sent: Thursday, December 13, 2007 10:59 AM
Subject: Re: Unknown event

I looked at other Idaho and Montana helicorders and they = recorded=20 it at the
same time.   It might be regional, but (as of = now) I=20 don't see it listed
anywhere.
Just guessing it must be greater = than a M3,=20 also guessing around 1000 miles
or closer?

Thanks,=20 Ted

.
----- Original Message -----
From: "J=F3n Fr=EDmann" = <jonfr@.........>
To: <psn-l@..............>
Sent= :=20 Thursday, December 13, 2007 9:50 AM
Subject: Re: Unknown=20 event


Hi

Is it possible that you did recored a regonal = earthquake ?

Regards.
--
J=F3n Fr=EDmann
http://www.jonfr.com
http://earthquakes.jonfr.comhttp://www.net303.net
http://www.mobile-coverage.com/<= /A>

__________________________________________________________
=
Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... =20 with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more=20 information.

_____________________________________________________= _____

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Unknown event From: Pete Rowe ptrowe@......... Date: Thu, 13 Dec 2007 10:16:26 -0800 (PST) Nothing here at that time in San Jose, Ted. Pete --- tchannel1@............ wrote: > Hi Folks, At about 10:52 utc we recorded and > unknown..........at least I do not see it published > anywhere yet. > Do you know? > > Thanks, Ted ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Thu, 13 Dec 2007 14:01:53 -0700 Hi Chris, On Dec 12, 2007 5:35 PM, wrote: > In a message dated 12/12/2007, paleoartifact@......... writes: > > I've tried both your ideas of copper sheet and pencil leads, in a > different (unintentional) diamagnetic > levitation variation model and thus far the results have been noteably > quite useful. > > Hi Meredith, > > I have also used D shaped pencil leads. I stick some say 32 thou sheet > onto a flat backing plate with double sided tape, apply the round lead to > the L edge of the plate and then sand off the top with new emery paper on a > flat backing plate. You can 'roll' the lead carefully off the sticky tape > when you have finished sanding. If you have any problems, heat from a hair > drier can help a lot. > **** The above would help in the glueing aspect of course. Its difficult to maintain close size/sanded consistency. > > You would likely get quite strong damping if you made the Cu end foils > wider so that they overlapped the end magnet + 1/2 the outside magnets? The > field gradients should be considerable here? > **** Yes, indeed with adding 1/2" wide copper foil the dampening is variable and including up to overdampened. I removed the extra two end magnets and tried using foil only one end and even that is quite sufficient. This likely means that the "open end" could bear a optical flag eventually. > > Have you suffered from freezing rain in Denver? There have been some > very catastrophic looking pictures on TV. The last time we had this problem > was back in the 1940s. > **** No ice buildup like they got in Kansas afew days back. Perhaps 8" of snow over a weeks time. Nebraska got it bad ~ last December or so, with ice; as, it toppled even fences with ~ 1" thick ice over single strand fence wire. Massive power outages & etc. > > The two part acrylic glue is very good for sticking carbon. Devweld > 530 should be available to you in twin tubes? I use Holdtite 3295. > **** Think I'll try 3m scotch-weld DP810 structural 2 part acrylic adhesive; at least that I can get locally initially. I envy your european glues.....they have a number of really excellent glues that are vastly superior to likely any common American brands. > > Hope that you are all well! > **** We're doing as well as we can under the circumstances. Hope your health is fine also! Take care, Meredith > > Regards, > > Chris > > Hi Chris,

On Dec 12, 2007 5:35 PM, <ChrisAtUpw@.......> wrote:
In a message dated 12/12/2007, paleoartifact@......... writes:
I've tried both your ideas of copper sheet and pencil leads, in a different (unintentional) diamagnetic
levitation variation model and thus far the results have been noteably quite useful. 
Hi Meredith,
 
    I have also used D shaped pencil leads. I stick some say 32 thou sheet onto a flat backing plate with double sided tape, apply the round lead to the L edge of the plate and then sand off the top with new emery paper on a flat backing plate. You can 'roll' the lead carefully off the sticky tape when you have finished sanding. If you have any problems, heat from a hair drier can help a lot. 
 
**** The above would help in the glueing aspect of course.  Its difficult to maintain close size/sanded consistency.
 
    You would likely get quite strong damping if you made the Cu end foils wider so that they overlapped the end magnet + 1/2 the outside magnets?  The field gradients should be considerable here?
 
**** Yes, indeed with adding 1/2" wide copper foil the dampening is variable and including up to overdampened.  I removed the extra
two end magnets and tried using foil only one end and even that is quite sufficient.  This likely means that the "open end" could bear a optical flag eventually. 
 
    Have you suffered from freezing rain in Denver? There have been some very catastrophic looking pictures on TV. The last time we had this problem was back in the 1940s. 
 
**** No ice buildup like they got in Kansas afew days back.  Perhaps 8" of snow over a weeks time.  Nebraska got it bad ~ last December or so, with ice; as, it toppled even fences with ~ 1" thick ice over single strand fence wire.  Massive power outages & etc.
 
 
    The two part acrylic glue is very good for sticking carbon. Devweld 530 should be available to you in twin tubes? I use Holdtite 3295.
 
**** Think I'll try 3m scotch-weld DP810 structural 2 part acrylic adhesive; at least that I can get locally initially.  I envy your european
glues.....they have a number of really excellent glues that are vastly superior to likely any common American brands.  
 
    Hope that you are all well!
 
**** We're doing as well as we can under the circumstances.  Hope your health is fine also!
Take care, Meredith
 
    Regards,
 
    Chris
 

Subject: I guess this is it. From: tchannel1@............ Date: Thu, 13 Dec 2007 21:23:32 -0700 Hi Folks, I think this must be the Unidentified event I asked about. = http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2007kwa1.php It was a 3.8M Southern Idaho, about 116km, 72 miles from here. Now I = can process it. Thanks everyone for you input. Ted
Hi Folks,  I think this must be = the=20 Unidentified event I asked about.   http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2007kwa1.p= hp
It was a 3.8M Southern Idaho, about = 116km, 72 miles=20 from here.   Now I can process it.
 
Thanks everyone for you = input.
Ted
Subject: Re: General Diamagnetic Tiltmeter Improvements From: "meredith lamb" paleoartifact@......... Date: Fri, 14 Dec 2007 08:55:18 -0700 Hi Chris and all interested parties, Mistake notice: This diamagnetic tiltmeter model does require the use of copper dampening foil on both ends; otherwise the dampening isn't sufficient for both directions it could respond too. Take care, Meredith Lamb (snip) > > In a message dated 12/12/2007, paleoartifact@......... writes: > > > > > > > > **** Yes, indeed with adding 1/2" wide copper foil the dampening is > variable and including up to overdampened. I removed the extra > two end magnets and tried using foil only one end and even that is quite > sufficient. This likely means that the "open end" could bear a optical flag > eventually. > > >
Hi Chris and all interested parties,
 
Mistake notice:  This diamagnetic tiltmeter model does require the use of copper dampening foil on both ends; otherwise the
dampening isn't sufficient for both directions it could respond too. 
 
Take care, Meredith Lamb 

(snip)
 

In a message dated 12/12/2007, paleoartifact@......... writes:
 
**** Yes, indeed with adding 1/2" wide copper foil the dampening is variable and including up to overdampened.  I removed the extra
two end magnets and tried using foil only one end and even that is quite sufficient.  This likely means that the "open end" could bear a optical flag eventually. 
Subject: Anniversary clock spring From: tchannel1@............ Date: Sat, 15 Dec 2007 11:40:31 -0700 Hi Folks, This is an observation and a question. I have an Anniversary = clock, perhaps also called a 500 day clock, as you only need to wind it = once a year, or so. I know very little about clocks, but have worked = on a few clock movements and escapements. I have some old clocks which = are 8 day movements. I wondered why the big difference in power = consumptions, and spring properties between the two types. The 8 day movements use a short pendulum which is maybe 1/2 second = natural period. The anniversary clock has a short spring, instead of a = pendulum, which is like a flat thread. This spring is fixed at the top = and has four masses, brass balls on the free end. One period of this = spring is about 8 seconds. The mass in motion, twist the thread like = spring, until the power of the spring stops the mass, and swings it in = the opposite direction. A different coiled mainspring then add a kick = to the mass and the cycle repeats. Always looking for different ways to obtain a 20 second period, I took a = band saw blade, cut it and suspended it from my shop ceiling. It now = hangs similar to the thread like movement spring of the anniversary = clock. At the bottom of the 72" band saw blade, I attached a 36" = yardstick. This now looks like an inverted "T". I added a mass to = both ends of the yardstick. I twisted the spring and released it. I = found it rotated back and forth and it period was about 8 seconds. I = keep adding equal mass to both end of the yardstick, and the period was = 24 seconds. The yardstick seems to always come to rest at the same point, as the = spring wants to untwist. My question: Has anyone tried this approach? If so, could anyone = direct me to more information about it on the internet? Thanks, Ted

Hi Folks,  This is an observation and a question.  I have = an=20 Anniversary clock, perhaps also called a 500 day clock, as you only need = to wind=20 it once a year, or so.   I know very little about clocks, but = have=20 worked on a few clock movements and escapements.   I have some = old=20 clocks which are 8 day movements.   I wondered why the big = difference=20 in power consumptions, and spring properties between the two types.

The 8 day movements use a short pendulum which is maybe 1/2=20 second natural period.  The anniversary clock has a short = spring,=20 instead of a pendulum, which is  like a flat thread.  This = spring is=20 fixed at the top and has four masses, brass balls on the free end.  = One=20 period of this spring is about  8 seconds.   The mass in = motion,=20 twist the thread like spring, until the power of the spring stops the = mass, and=20 swings it in the opposite direction.  A different=20 coiled mainspring then add a kick to the mass and the cycle = repeats.

Always looking for different ways to obtain a 20 second period, I = took a band=20 saw blade, cut it and suspended it from my shop ceiling.  It now = hangs=20 similar to the thread like movement spring of the anniversary = clock.  At=20 the bottom of the 72" band saw blade, I attached a 36" yardstick.  = This now=20 looks like an inverted "T".   I added a mass to both ends of = the=20 yardstick.  I twisted the spring and released it.   I = found it=20 rotated back and forth and it period was about 8 seconds.  I keep = adding=20 equal mass to both end of the yardstick, and the period was 24 = seconds.

 The yardstick seems to always come to rest at the same point, = as the=20 spring wants to untwist.

My question:  Has anyone tried this approach?   If so, =  could anyone direct me to more information about it on the = internet?

Thanks, Ted

Subject: Re: Anniversary clock spring From: "Connie and Jim Lehman" lehmancj@........... Date: Sat, 15 Dec 2007 17:56:53 -0500 Ted--there is some neat physics in the inverted T torsional balance. = The increase of period with increased masses added makes for a nice = graph in a physics lab, and there are related aspects of interest. = Perhaps stability would be a big problem, but set it up with a damping = mechanism, and give it a try. Seasons Greetings Jim Lehman ----- Original Message -----=20 From: tchannel1@............... To: psn=20 Sent: Saturday, December 15, 2007 1:40 PM Subject: Anniversary clock spring Hi Folks, This is an observation and a question. I have an = Anniversary clock, perhaps also called a 500 day clock, as you only need = to wind it once a year, or so. I know very little about clocks, but = have worked on a few clock movements and escapements. I have some old = clocks which are 8 day movements. I wondered why the big difference in = power consumptions, and spring properties between the two types. The 8 day movements use a short pendulum which is maybe 1/2 second = natural period. The anniversary clock has a short spring, instead of a = pendulum, which is like a flat thread. This spring is fixed at the top = and has four masses, brass balls on the free end. One period of this = spring is about 8 seconds. The mass in motion, twist the thread like = spring, until the power of the spring stops the mass, and swings it in = the opposite direction. A different coiled mainspring then add a kick = to the mass and the cycle repeats. Always looking for different ways to obtain a 20 second period, I took = a band saw blade, cut it and suspended it from my shop ceiling. It now = hangs similar to the thread like movement spring of the anniversary = clock. At the bottom of the 72" band saw blade, I attached a 36" = yardstick. This now looks like an inverted "T". I added a mass to = both ends of the yardstick. I twisted the spring and released it. I = found it rotated back and forth and it period was about 8 seconds. I = keep adding equal mass to both end of the yardstick, and the period was = 24 seconds. The yardstick seems to always come to rest at the same point, as the = spring wants to untwist. My question: Has anyone tried this approach? If so, could anyone = direct me to more information about it on the internet? Thanks, Ted
Ted--there is some neat physics in the = inverted T=20 torsional balance.  The increase of period with increased masses = added=20 makes for a nice graph in a physics lab, and there are related aspects = of=20 interest.  Perhaps stability would be a big problem, but set it up = with a=20 damping mechanism, and give it a=20 try.         Seasons=20 Greetings    Jim Lehman
----- Original Message -----
From:=20 tchannel1@............ =
To: psn
Sent: Saturday, December 15, = 2007 1:40=20 PM
Subject: Anniversary clock = spring

Hi Folks,  This is an observation and a question.  I have = an=20 Anniversary clock, perhaps also called a 500 day clock, as you only = need to=20 wind it once a year, or so.   I know very little about = clocks, but=20 have worked on a few clock movements and escapements.   I = have some=20 old clocks which are 8 day movements.   I wondered why the = big=20 difference in power consumptions, and spring properties between the = two=20 types.

The 8 day movements use a short pendulum which is maybe 1/2=20 second natural period.  The anniversary clock has a short = spring,=20 instead of a pendulum, which is  like a flat thread.  This = spring is=20 fixed at the top and has four masses, brass balls on the free = end.  One=20 period of this spring is about  8 seconds.   The mass = in=20 motion, twist the thread like spring, until the power of the spring = stops the=20 mass, and swings it in the opposite direction.  A different=20 coiled mainspring then add a kick to the mass and the cycle = repeats.

Always looking for different ways to obtain a 20 second period, I = took a=20 band saw blade, cut it and suspended it from my shop ceiling.  It = now=20 hangs similar to the thread like movement spring of the anniversary=20 clock.  At the bottom of the 72" band saw blade, I attached a 36" = yardstick.  This now looks like an inverted "T".   I = added a=20 mass to both ends of the yardstick.  I twisted the spring and = released=20 it.   I found it rotated back and forth and it period was = about 8=20 seconds.  I keep adding equal mass to both end of the yardstick, = and the=20 period was 24 seconds.

 The yardstick seems to always come to rest at the same point, = as the=20 spring wants to untwist.

My question:  Has anyone tried this approach?   If = so,=20  could anyone direct me to more information about it on the = internet?

Thanks, Ted

Subject: Re: Anniversary clock spring From: "Les LaZar" llazar@.................. Date: Sat, 15 Dec 2007 16:01:51 -0800 How would a seismic wave, passing by an inverted T torsional balance, = impart any torsional motion to the horizontal bar and the masses? Just = wondering. Les LaZar ----- Original Message -----=20 From: Connie and Jim Lehman=20 To: psn-l@................. Sent: Saturday, December 15, 2007 2:56 PM Subject: Re: Anniversary clock spring Ted--there is some neat physics in the inverted T torsional balance. = The increase of period with increased masses added makes for a nice = graph in a physics lab, and there are related aspects of interest. = Perhaps stability would be a big problem, but set it up with a damping = mechanism, and give it a try. Seasons Greetings Jim Lehman ----- Original Message -----=20 From: tchannel1@............... To: psn=20 Sent: Saturday, December 15, 2007 1:40 PM Subject: Anniversary clock spring Hi Folks, This is an observation and a question. I have an = Anniversary clock, perhaps also called a 500 day clock, as you only need = to wind it once a year, or so. I know very little about clocks, but = have worked on a few clock movements and escapements. I have some old = clocks which are 8 day movements. I wondered why the big difference in = power consumptions, and spring properties between the two types. The 8 day movements use a short pendulum which is maybe 1/2 second = natural period. The anniversary clock has a short spring, instead of a = pendulum, which is like a flat thread. This spring is fixed at the top = and has four masses, brass balls on the free end. One period of this = spring is about 8 seconds. The mass in motion, twist the thread like = spring, until the power of the spring stops the mass, and swings it in = the opposite direction. A different coiled mainspring then add a kick = to the mass and the cycle repeats. Always looking for different ways to obtain a 20 second period, I = took a band saw blade, cut it and suspended it from my shop ceiling. It = now hangs similar to the thread like movement spring of the anniversary = clock. At the bottom of the 72" band saw blade, I attached a 36" = yardstick. This now looks like an inverted "T". I added a mass to = both ends of the yardstick. I twisted the spring and released it. I = found it rotated back and forth and it period was about 8 seconds. I = keep adding equal mass to both end of the yardstick, and the period was = 24 seconds. The yardstick seems to always come to rest at the same point, as = the spring wants to untwist. My question: Has anyone tried this approach? If so, could anyone = direct me to more information about it on the internet? Thanks, Ted
How would a seismic wave, passing by an = inverted T=20 torsional balance, impart any torsional motion to the horizontal bar and = the=20 masses?  Just wondering.
 
Les LaZar
 
----- Original Message -----
From:=20 Connie and=20 Jim Lehman
Sent: Saturday, December 15, = 2007 2:56=20 PM
Subject: Re: Anniversary clock=20 spring

Ted--there is some neat physics in = the inverted T=20 torsional balance.  The increase of period with increased masses = added=20 makes for a nice graph in a physics lab, and there are related aspects = of=20 interest.  Perhaps stability would be a big problem, but set it = up with a=20 damping mechanism, and give it a=20 try.         Seasons=20 Greetings    Jim Lehman
----- Original Message -----
From:=20 tchannel1@............ =
To: psn
Sent: Saturday, December 15, = 2007 1:40=20 PM
Subject: Anniversary clock = spring

Hi Folks,  This is an observation and a question.  I = have an=20 Anniversary clock, perhaps also called a 500 day clock, as you only = need to=20 wind it once a year, or so.   I know very little about = clocks, but=20 have worked on a few clock movements and escapements.   I = have=20 some old clocks which are 8 day movements.   I wondered = why the=20 big difference in power consumptions, and spring properties between = the two=20 types.

The 8 day movements use a short pendulum which is maybe 1/2=20 second natural period.  The anniversary clock has a short = spring,=20 instead of a pendulum, which is  like a flat thread.  This = spring=20 is fixed at the top and has four masses, brass balls on the free = end. =20 One period of this spring is about  8 seconds.   The = mass in=20 motion, twist the thread like spring, until the power of the spring = stops=20 the mass, and swings it in the opposite direction.  A = different=20 coiled mainspring then add a kick to the mass and the cycle=20 repeats.

Always looking for different ways to obtain a 20 second period, I = took a=20 band saw blade, cut it and suspended it from my shop ceiling.  = It now=20 hangs similar to the thread like movement spring of the anniversary=20 clock.  At the bottom of the 72" band saw blade, I attached a = 36"=20 yardstick.  This now looks like an inverted "T".   I = added a=20 mass to both ends of the yardstick.  I twisted the spring and = released=20 it.   I found it rotated back and forth and it period was = about 8=20 seconds.  I keep adding equal mass to both end of the = yardstick, and=20 the period was 24 seconds.

 The yardstick seems to always come to rest at the same = point, as=20 the spring wants to untwist.

My question:  Has anyone tried this approach?   If = so,=20  could anyone direct me to more information about it on the=20 internet?

Thanks, = Ted

Subject: Re: Anniversary clock spring From: tchannel1@............ Date: Sat, 15 Dec 2007 17:27:01 -0700 Les, I think some of the others may answer this better than me, but I = would suspect this would act the same as other sensors: The movement of the earth resulting from an earthquake, will move the = entire apparatuses, and the room it is in. However the mass at the ends = of the inverted T will move less, relative to the sensor and the room it = is in. Ted ----- Original Message -----=20 From: Les LaZar=20 To: psn-l@................. Sent: Saturday, December 15, 2007 5:01 PM Subject: Re: Anniversary clock spring How would a seismic wave, passing by an inverted T torsional balance, = impart any torsional motion to the horizontal bar and the masses? Just = wondering. Les LaZar ----- Original Message -----=20 From: Connie and Jim Lehman=20 To: psn-l@................. Sent: Saturday, December 15, 2007 2:56 PM Subject: Re: Anniversary clock spring Ted--there is some neat physics in the inverted T torsional balance. = The increase of period with increased masses added makes for a nice = graph in a physics lab, and there are related aspects of interest. = Perhaps stability would be a big problem, but set it up with a damping = mechanism, and give it a try. Seasons Greetings Jim Lehman ----- Original Message -----=20 From: tchannel1@............... To: psn=20 Sent: Saturday, December 15, 2007 1:40 PM Subject: Anniversary clock spring Hi Folks, This is an observation and a question. I have an = Anniversary clock, perhaps also called a 500 day clock, as you only need = to wind it once a year, or so. I know very little about clocks, but = have worked on a few clock movements and escapements. I have some old = clocks which are 8 day movements. I wondered why the big difference in = power consumptions, and spring properties between the two types. The 8 day movements use a short pendulum which is maybe 1/2 second = natural period. The anniversary clock has a short spring, instead of a = pendulum, which is like a flat thread. This spring is fixed at the top = and has four masses, brass balls on the free end. One period of this = spring is about 8 seconds. The mass in motion, twist the thread like = spring, until the power of the spring stops the mass, and swings it in = the opposite direction. A different coiled mainspring then add a kick = to the mass and the cycle repeats. Always looking for different ways to obtain a 20 second period, I = took a band saw blade, cut it and suspended it from my shop ceiling. It = now hangs similar to the thread like movement spring of the anniversary = clock. At the bottom of the 72" band saw blade, I attached a 36" = yardstick. This now looks like an inverted "T". I added a mass to = both ends of the yardstick. I twisted the spring and released it. I = found it rotated back and forth and it period was about 8 seconds. I = keep adding equal mass to both end of the yardstick, and the period was = 24 seconds. The yardstick seems to always come to rest at the same point, as = the spring wants to untwist. My question: Has anyone tried this approach? If so, could = anyone direct me to more information about it on the internet? Thanks, Ted
Les,   I think some of the = others may=20 answer this better than me, but I would suspect this would act the same = as other=20 sensors:
 
The movement of the earth resulting = from an=20 earthquake, will move the entire apparatuses, and the room it is = in. =20 However the mass at the ends of the inverted T will move less, relative = to the=20 sensor and the room it is in.
 
Ted
----- Original Message -----
From:=20 Les=20 LaZar
Sent: Saturday, December 15, = 2007 5:01=20 PM
Subject: Re: Anniversary clock=20 spring

How would a seismic wave, passing by = an inverted=20 T torsional balance, impart any torsional motion to the horizontal bar = and the=20 masses?  Just wondering.
 
Les LaZar
 
----- Original Message -----
From:=20 Connie and=20 Jim Lehman
Sent: Saturday, December 15, = 2007 2:56=20 PM
Subject: Re: Anniversary = clock=20 spring

Ted--there is some neat physics in = the inverted=20 T torsional balance.  The increase of period with increased = masses=20 added makes for a nice graph in a physics lab, and there are related = aspects=20 of interest.  Perhaps stability would be a big problem, but set = it up=20 with a damping mechanism, and give it a=20 try.         Seasons=20 Greetings    Jim Lehman
----- Original Message ----- =
From:=20 tchannel1@............ =
To: psn
Sent: Saturday, December = 15, 2007=20 1:40 PM
Subject: Anniversary clock=20 spring

Hi Folks,  This is an observation and a question.  I = have an=20 Anniversary clock, perhaps also called a 500 day clock, as you = only need=20 to wind it once a year, or so.   I know very little = about=20 clocks, but have worked on a few clock movements and=20 escapements.   I have some old clocks which are 8 day=20 movements.   I wondered why the big difference in power=20 consumptions, and spring properties between the two types.

The 8 day movements use a short pendulum which is = maybe 1/2=20 second natural period.  The anniversary clock has a = short=20 spring, instead of a pendulum, which is  like a flat = thread. =20 This spring is fixed at the top and has four masses, brass balls = on the=20 free end.  One period of this spring is about  8=20 seconds.   The mass in motion, twist the thread like = spring,=20 until the power of the spring stops the mass, and swings it in the = opposite direction.  A different coiled mainspring = then add=20 a kick to the mass and the cycle repeats.

Always looking for different ways to obtain a 20 second period, = I took=20 a band saw blade, cut it and suspended it from my shop = ceiling.  It=20 now hangs similar to the thread like movement spring of the = anniversary=20 clock.  At the bottom of the 72" band saw blade, I attached a = 36"=20 yardstick.  This now looks like an inverted "T".   = I added=20 a mass to both ends of the yardstick.  I twisted the spring = and=20 released it.   I found it rotated back and forth and it = period=20 was about 8 seconds.  I keep adding equal mass to both end of = the=20 yardstick, and the period was 24 seconds.

 The yardstick seems to always come to rest at the same = point, as=20 the spring wants to untwist.

My question:  Has anyone tried this approach?   = If so,=20  could anyone direct me to more information about it on the=20 internet?

Thanks,=20 Ted

= Subject: Re: Anniversary clock spring From: John Lahr johnjan@........ Date: Sat, 15 Dec 2007 21:36:50 -0800 Hi Ted, The sensor that you've designed will be sensitive to rotations of the ground with a vertical axis. The problem is that such rotations are very small and thus difficult to detect. This is a budding field of seismology. See, for example: http://pubs.usgs.gov/of/2007/1144/ Of course the inverted T will also swing like a normal pendulum with period determined by the overall length of the blade, unless it's constrained to remain vertical. Cheers, John At 10:40 AM 12/15/2007, you wrote: >Hi Folks, This is an observation and a question. I have an >Anniversary clock, perhaps also called a 500 day clock, as you only >need to wind it once a year, or so. I know very little about >clocks, but have worked on a few clock movements and >escapements. I have some old clocks which are 8 day movements. I >wondered why the big difference in power consumptions, and spring >properties between the two types. > >The 8 day movements use a short pendulum which is maybe 1/2 second >natural period. The anniversary clock has a short spring, instead >of a pendulum, which is like a flat thread. This spring is fixed >at the top and has four masses, brass balls on the free end. One >period of this spring is about 8 seconds. The mass in motion, >twist the thread like spring, until the power of the spring stops >the mass, and swings it in the opposite direction. A different >coiled mainspring then add a kick to the mass and the cycle repeats. > >Always looking for different ways to obtain a 20 second period, I >took a band saw blade, cut it and suspended it from my shop >ceiling. It now hangs similar to the thread like movement spring of >the anniversary clock. At the bottom of the 72" band saw blade, I >attached a 36" yardstick. This now looks like an inverted "T". I >added a mass to both ends of the yardstick. I twisted the spring >and released it. I found it rotated back and forth and it period >was about 8 seconds. I keep adding equal mass to both end of the >yardstick, and the period was 24 seconds. > > The yardstick seems to always come to rest at the same point, as > the spring wants to untwist. > >My question: Has anyone tried this approach? If so, could anyone >direct me to more information about it on the internet? > >Thanks, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Anniversary clock spring From: ChrisAtUpw@....... Date: Sun, 16 Dec 2007 05:12:57 EST In a message dated 2007/12/16, tchannel1@............ writes: > The movement of the earth resulting from an earthquake, will move the > entire apparatuses, and the room it is in. However the mass at the ends of the > inverted T will move less, relative to the sensor and the room it is in. Hi Ted, A T bar torsion system is fine for clock timing, provided you have a strip / wire of Elinvar to suspend it, otherwise the torsional temperature coefficient is too great. The low energy requirement for clocks is a consequence of the long period and simple gearing. However, I don't see how you would use it as a seismic sensor? There are two modes of oscillation, the torsional one and the whole body as a simple pendulum. Only the rotational one has a long period and this is not strongly excited by moving the suspension, unless the quake is local, when there may be rotational components. If you look back into the history of seismometers, one type which does not seem to have be much used, except for miniature quartz devices, is the torsional type . It has a horizontal light beam with a weight on the end and two suspension wires spaced a short distance apart, the center one going upwards and the lower one going downwards. They can have quite long periods and were mentioned in one of your pendulum references. You might need Invar wire. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Frame \ \ WIRE \ _____ --------\---------------------------------------------I I MASS I------------------------------------------------------I____I \ RIGID ARM \ \ WIRE \ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Frame Regards, Chris Chapman In a me= ssage dated 2007/12/16, tchannel1@............ writes:

The movement of the earth resul= ting from an earthquake, will move the entire apparatuses, and the room it i= s in.  However the mass at the ends of the inverted T will move less, r= elative to the sensor and the room it is in.


Hi Ted,

       A T bar torsion system is fine for cloc= k timing, provided you have a strip / wire of Elinvar to suspend it, otherwi= se the torsional temperature coefficient is too great. The low energy requir= ement for clocks is a consequence of the long period and simple gearing.

       However, I don't see how you would use=20= it as a seismic sensor? There are two modes of oscillation, the torsional on= e and the whole body as a simple pendulum. Only the rotational one has a lon= g period and this is not strongly excited by moving the suspension, unless t= he quake is local, when there may be rotational components.

       If you look back into the history of se= ismometers, one type which does not seem to have be much used, except for mi= niature quartz devices, is the torsional type . It has a horizontal light be= am with a weight on the end and two suspension wires spaced a short distance= apart, the center one going upwards and the lower one going downwards. They= can have quite long periods and were mentioned in one of your pendulum refe= rences. You might need Invar wire.

            &nbs= p;           XXXXXXXXXXXXX= XXXXXXXXXXXXXXXXXXXXXXX   Frame      = ;            &nb= sp;    
            &nbs= p;             \=
            &nbs= p;            &n= bsp;  \   WIRE        = ;            &nb= sp;            &= nbsp;         
            &nbs= p;            &n= bsp;    \        &nbs= p;            &n= bsp;            =              ___= __
            &nbs= p;           --------\----= -----------------------------------------I     &nbs= p;  I MASS
            &nbs= p;           I------------= ------------------------------------------I____I
            &nbs= p;            \ =             &nbs= p;     RIGID ARM
            &nbs= p;            &n= bsp; \
            &nbs= p;            &n= bsp;   \   WIRE
            &nbs= p;            &n= bsp;     \
            &nbs= p;            XXXXXXX= XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Frame

       Regards,

       Chris Chapman Subject: 30 second period From: tchannel1@............ Date: Mon, 17 Dec 2007 18:10:19 -0700 Hi Folks, I am pursuing, the concept of a "Inverted T torsion spring" = I just want to experiment with a mock up, in the shop, to study the = idea. I started with a 3/8" discarded band saw blade, cut it into a ribbon and = hung it from the shop ceiling. It measured about 78" top to bottom. I Secured the top of the band to a beam in the ceiling, and to the = bottom of the band, I attached a 5/8" wood dowel, 40" long centered, 20" = on either side. This formed and inverted T, which if twisted would return to the same = spot, as the flat band of steel untwisted. I will call this spot, the center line. To the bottom of the wood dowel, centered, in line with the band saw = blade, I placed a small finishing nail, pointing down. This nail fits = into a small hole in the bottom of a coffee can, The nail and coffee = can act as a retainer so the band can only rotate. The band can no = longer swing like a pendulum. The coffee can is waited so it can't = move. There is a very small space between the nail and the coffee can = hole, so it does not rub. I balanced two 1 1/4 # weights on the wood dowel, one on each side, at = 14" from the center of the dowel. This first thing I noticed, was the length of time the torsion spring = would cycle, once moved, (twisted) about 8" from the center line, and = released. It rotated back and forth, for 5 hours, from 3:58 pm until 9:00pm, and = you could still see some movement. The two masses 14" from center, arrangement resulted in a cycle of 27 = seconds, and at 16" the cycle was 32 seconds. I add a pair of magnets and an Aluminum plate as a damper, on one end of = the dowel, and a pick up coil and magnet to the other end of the dowel. It is all connected and ready to record. I covered most of the sensor = with a makeshift tent of old blankets to keep draft away. A small hole = in the top of the tent allows the band saw blade, to pass. It all seems to be working. I hope to leave it set up and record a few = earthquakes, before I must remove it, so I can continue my other shop = work. When and if I get some recordings, I will post them on PSN under the = name TCIDTS for Torsion Spring. This is all very interesting to me. With very little effort I could = get a 32 second period, by adding more mass or a longer dowel, I could = get even longer. Thanks, Ted............Ps.......I did take the time to cut all the teeth = off the band saw blade, so now it looks like a ribbon of steel about = 3/8" x 78". and the finial period is about 30 seconds.
Hi Folks,  I am pursuing, the = concept of a=20 "Inverted T torsion spring"  I just want to experiment with a mock = up, in=20 the shop, to study the idea.
 
I started with a 3/8" discarded band = saw blade, cut=20 it into a ribbon and hung it from the shop ceiling.  It measured = about 78"=20 top to bottom.
I Secured the top of the band to a beam = in the=20 ceiling, and to the bottom of the band, I attached a 5/8" wood dowel, = 40"=20 long centered, 20" on either side.
 
This formed and inverted T, which if = twisted would=20 return to the same spot, as the flat band of steel = untwisted.
I will call this spot, the = center=20 line.
 
To the bottom of the wood dowel, = centered, in line=20 with the band saw blade, I placed a small finishing nail, pointing=20 down.  This nail fits into a small hole in the bottom of a coffee=20 can,  The nail and coffee can act as a retainer so the band can = only=20 rotate.  The band can no longer swing like a pendulum.  The = coffee can=20 is waited so it can't move.  There is a very small space between = the nail=20 and the coffee can hole, so it does not rub.
 
I balanced two 1 1/4 # weights on the = wood dowel,=20 one on each side, at 14" from the center of the dowel.
 
This first thing I noticed, was the = length of time=20 the torsion spring would cycle, once moved, (twisted) about 8" from = the=20 center line, and released.
It rotated back and forth, for 5 hours, = from 3:58=20 pm until 9:00pm, and you could still see some movement.
 
The two masses 14" from center, = arrangement=20 resulted in a cycle of 27 seconds, and at 16"  the cycle was 32=20 seconds.
 
I add a pair of magnets and an Aluminum = plate as a=20 damper, on one end of the dowel, and a pick up coil and magnet to the = other end=20 of the dowel.
 
It is all connected and ready to=20 record.   I covered most of the sensor with a makeshift tent = of old=20 blankets to keep draft away.   A small hole in the top of the = tent=20 allows the band saw blade, to pass.
 
It all seems to be working.   = I hope to=20 leave it set up and record a few earthquakes, before I must remove it, = so I can=20 continue my other shop work.
 
When and if I get some recordings, =  I will=20 post them on PSN under the name TCIDTS   for Torsion=20 Spring.
 
This is all very interesting to=20 me.   With very little effort I could get a 32 second = period, by=20 adding more mass or a longer dowel, I could get even = longer.
 
Thanks, Ted............Ps.......I did = take the time=20 to cut all the teeth off the band saw blade, so now it looks like a = ribbon of=20 steel about 3/8" x 78".  and the finial period is about 30=20 seconds.
 
 
 
 
Subject: Re: 30 second period From: ChrisAtUpw@....... Date: Mon, 17 Dec 2007 21:26:03 EST In a message dated 2007/12/18 , tchannel1@............ writes: > Hi Folks, I am pursuing, the concept of a "Inverted T torsion spring" I > just want to experiment with a mock up, in the shop, to study the idea. Hi there, Why are you trying to use steel tape when piano wire is readily available and quite cheap? It can give longer periods. If you use a vertical rod connected to the centre of the horizontal dumbell and clamp sections of piano wire in both it's ends, you can get quite a rigid system which does not wave about in the breeze.... Regards, Chris Chapman In a me= ssage dated 2007/12/18 , tchannel1@............ writes:

Hi Folks,  I am pursuing,=20= the concept of a "Inverted T torsion spring"  I just want to experiment= with a mock up, in the shop, to study the idea.


Hi there,

       Why are you trying to use steel tape wh= en piano wire is readily available and quite cheap? It can give longer perio= ds.

       If you use a vertical rod connected to=20= the centre of the horizontal dumbell and clamp sections of piano wire in bot= h it's ends, you can get quite a rigid system which does not wave about in t= he breeze....

       Regards,

       Chris Chapman Subject: Re: 30 second period From: tchannel1@............ Date: Mon, 17 Dec 2007 21:31:48 -0700 Hi Chris, My reason, was I had the band saw blade. I think I will = try your idea, and I do have some music wire, and can get some piano = wire. Your idea would stabilize the top and the bottom, so that would = be a better way to go. Thanks, Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Monday, December 17, 2007 7:26 PM Subject: Re: 30 second period In a message dated 2007/12/18 , tchannel1@............ writes: Hi Folks, I am pursuing, the concept of a "Inverted T torsion = spring" I just want to experiment with a mock up, in the shop, to study = the idea. Hi there, Why are you trying to use steel tape when piano wire is readily = available and quite cheap? It can give longer periods. If you use a vertical rod connected to the centre of the = horizontal dumbell and clamp sections of piano wire in both it's ends, = you can get quite a rigid system which does not wave about in the = breeze.... Regards, Chris Chapman
Hi Chris,   My reason, was I = had the band=20 saw blade.   I think I will try your idea, and I do have some = music=20 wire, and can get some piano wire.  Your idea  would = stabilize=20 the top and the bottom, so that would be a better way to go.   = Thanks,
Ted
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Monday, December 17, 2007 = 7:26=20 PM
Subject: Re: 30 second = period

In a=20 message dated 2007/12/18 , tchannel1@............=20 writes:

Hi Folks,  I am pursuing, the concept of a = "Inverted T=20 torsion spring"  I just want to experiment with a mock up, in = the shop,=20 to study the idea.

Hi=20 there,

       Why are you trying = to use=20 steel tape when piano wire is readily available and quite cheap? It = can give=20 longer periods.

       If you use = a=20 vertical rod connected to the centre of the horizontal dumbell and = clamp=20 sections of piano wire in both it's ends, you can get quite a rigid = system=20 which does not wave about in the=20 breeze....

      =20 Regards,

       Chris = Chapman=20 Subject: 30 second period From: tchannel1@............ Date: Tue, 18 Dec 2007 12:17:58 -0700 Hi Folks, I will leave my Band Saw Blade sensor set up until I record a = few earthquakes, just to see how they look. Meanwhile the sensor is in = the garage and is picking up a lot of noise, both from the road = construction, near by, and me moving around the garage. However it all = quiets down at night. After this test, I do wish to pursue the idea of using music wire, piano = wire, or the like. I also will secure both the top and bottom of the = wire, and put the barbell in the center. Before I make the next device, could someone answer these questions. 1. I know the shorter the wire the shorter the period, but If I use two = wires, say 36", one on top of the horz and one on the bottom of the = horz, would the period be the same as using one, 72" wire, on the top only? Or would it just reflect the length of the = top wire only, and not the bottom wire? 2. Using the same mass and length of wire, would thinner wire result in = a longer period? 3. This was a surprise: As I mentioned, the isolation continued for = 5hrs. I have tried different pendulums, with different hinges. I have = tried different springs. These would only cycle for a few seconds and = up to maybe 30 mins. Can someone explain the different, of the longer = periond of the torsion spring? =20 This is all new to me, but I can see why the Anniversary clock can run = for so many days without winding. I have experimented with clock = escapements, and have made some wooden clocks. I just find it = interesting, but never saw anything that continued to move, on its own, = like this torsion spring. Thanks, Ted
Hi Folks,  I will leave my Band = Saw Blade=20 sensor set up until I record a few earthquakes, just to see how they = look. =20 Meanwhile the sensor is in the garage and is picking up a lot of noise, = both=20 from the road construction, near by, and me moving around the=20 garage.   However it all quiets down at = night.
 
After this test, I do wish to pursue = the idea of=20 using music wire, piano wire, or the like.   I also will = secure both=20 the top and bottom of the wire, and put the barbell in the = center.
 
Before I make the next device, could = someone answer=20 these questions.
 
1.  I know the shorter the wire = the shorter=20 the period, but If I use two wires, say 36", one on top of the horz and = one on=20 the bottom of the horz, would the period be the same as using = one,
72" wire, on the top only?   = Or would it=20 just reflect the length of the top wire only, and not the bottom=20 wire?
 
2.  Using the same mass and length = of wire,=20 would thinner wire result in a longer period?
 
3.  This was a surprise:  As = I mentioned,=20 the isolation continued for 5hrs.   I have tried different = pendulums,=20 with different hinges.  I have tried different springs.  These = would=20 only cycle for a few seconds and up to maybe 30 mins.   Can = someone=20 explain the different, of the longer periond of the torsion = spring?  =20
 
This is all new to me, but I can see = why the=20 Anniversary clock can run for so many days without winding.  I have = experimented with clock escapements, and have made some wooden = clocks.  I=20 just find it interesting, but never saw anything that continued to move, = on its=20 own, like this torsion spring.
 
Thanks, Ted
Subject: Re: 30 second period From: Brett Nordgren Brett3mr@............. Date: Tue, 18 Dec 2007 17:19:18 -0500 Ted, At 12:17 PM 12/18/2007 -0700, you wrote: >Hi Folks, I will leave my Band Saw Blade sensor set up until I record a >few earthquakes, just to see how they look. Meanwhile the sensor is in >the garage and is picking up a lot of noise, both from the road >construction, near by, and me moving around the garage. However it all >quiets down at night. > >After this test, I do wish to pursue the idea of using music wire, piano >wire, or the like. I also will secure both the top and bottom of the >wire, and put the barbell in the center. > >Before I make the next device, could someone answer these questions. > >1. I know the shorter the wire the shorter the period, but If I use two >wires, say 36", one on top of the horz and one on the bottom of the horz, >would the period be the same as using one, >72" wire, on the top only? Or would it just reflect the length of the >top wire only, and not the bottom wire? At first glance, I think the period would become 1/2 that of the original. The spring constant (or more properly the torsion coefficient, which is defined as the change in torque / change in angle) of each 36" spring would be twice that of the 72" and also, the total spring constant would be the sum of the upper and lower wires, making the total coefficient = 4X the original. The free period is the sqrt(mom of inertia / torsion coefficient) so after splitting the wire the period would be 1/2 the original. > 2. Using the same mass and length of wire, would thinner wire result in > a longer period? Yes, since the period is proportional to 1/sqrt(torsion coeff). For a given wire material, the torsion coefficient is proportional to Dia.^4 / Length. So cutting the diameter in half, reduces the torsion coefficient by a factor of 16, and so increases the period by a factor of 4. Note that doubling the length only increases the period by a factor of about 1.4. > 3. This was a surprise: As I mentioned, the isolation continued for > 5hrs. I have tried different pendulums, with different hinges. I have > tried different springs. These would only cycle for a few seconds and up > to maybe 30 mins. Can someone explain the different, of the longer > periond of the torsion spring? It turns out that the two types of pendulums would be measuring different things. Any motion, including the motion of a point on the earth, can be completely described by six parameters, three translation, straight-line motions: up-down, East-West, North-South, and three rotational motions: around a vertical axis, a N-S axis and an E-W axis. Seismographs normally measure the translations because for earthquake generated motion, they are usually much larger than the rotations. Early in the history of seismographs, as I recall, there was a debate going on whether horizontal pendulum designs were recording mainly translation or were also measuring rotation. Translation won. Some earthquake phases have both translation and rotation, which I believe are related to each other by the wavelength. For typical wavelengths through the ground, translation is usually much the larger effect, though your experiments are showing that it may be much easier to make a good long period torsion device than an equivalent regular pendulum. It might be that you could get useful results recording the much smaller rotations (about the vertical axis), simply because it was easier to make a much better torsion pendulum. Hope this helps, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: NZ quake rolls in From: Dave Nelson davenn@............... Date: Thu, 20 Dec 2007 19:56:10 +1100 hi all, a decent event offshr of the NE coast of the Nth Island of New= Zealand tonite Universal Time December 20 2007 at 7:55 NZ Daylight Time Thursday, December 20 2007 at 8:55 pm Latitude, Longitude 38.86=B0S, 178.52=B0E Focal Depth 40 km Richter magnitude ML 6.8 Region Hikurangi Trough Location =B7 50 km south-east of Gisborne =B7 400 km south-east of Auckland the USGS location is a bit out putting it onshore, ~ 20km SSW of Gisborne 38.992S 177.776E and 68km deep cheers Dave N Sydney -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.17.4/1189 - Release Date: 18/12/2007 = 9:40 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: ian ian@........... Date: Thu, 20 Dec 2007 09:01:14 +0000 coming in here too in Scotland, though a bit faint... See http://www.iasmith.com Cheers Ian Dave Nelson wrote: > > hi all, a decent event offshr of the NE coast of the Nth Island of > New Zealand > tonite > > Universal Time December 20 2007 at 7:55 > NZ Daylight Time Thursday, December 20 2007 at 8:55 pm > Latitude, Longitude 38.86°S, 178.52°E > Focal Depth 40 km > Richter magnitude ML 6.8 Region Hikurangi Trough > Location > · 50 km south-east of Gisborne > · 400 km south-east of Auckland > > the USGS location is a bit out putting it onshore, ~ 20km SSW of Gisborne > 38.992S 177.776E > > and 68km deep > > cheers > Dave N > Sydney > > > > > -- coming in here too in Scotland, though a bit faint...

See http://www.iasmith.com

Cheers

Ian

Dave Nelson wrote:

hi all,  a decent event offshr of the NE coast of the Nth Island of New Zealand
tonite

Universal Time December 20 2007 at 7:55
NZ Daylight Time Thursday, December 20 2007 at 8:55 pm
Latitude, Longitude 38.86°S, 178.52°E
Focal Depth 40 km
Richter magnitude ML 6.8 Region Hikurangi Trough
Location
·       50 km south-east of Gisborne
·       400 km south-east of Auckland

the USGS location is a bit out putting it onshore, ~ 20km SSW of Gisborne
38.992S   177.776E

and 68km deep

cheers
Dave N
Sydney






--

Subject: Re: NZ quake rolls in From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 20 Dec 2007 12:23:53 +0000 Hi According to EMSC the earthquake was on the island. Not far in, but inland anyway. More info can be seen here. http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D72867 Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: Mark Robinson mark.robinson@............... Date: Fri, 21 Dec 2007 01:56:06 +1300 Well felt here about 250km from the epicentre. Information from our local seismological agency: http://www.geonet.org.nz/earthquake/quakes/2839343g.html http://www.geonet.org.nz/earthquake/quakes/2839343g-maps.html http://magma.geonet.org.nz/maps/app?service=external/FeltReports&sp=S2839343g Local media: http://www.gisborneherald.co.nz/ http://www.stuff.co.nz/ http://www.nzherald.co.nz/ http://www.radionz.co.nz/news/home It was considerably stronger here than the 7.2 event of December 9th which was ~1800km away: http://www.geonet.org.nz/earthquake/quakes/2833367g.html Near real time shaking maps: http://www.geonet.org.nz/index.html And some interesting analysis of an ongoing swarm not so very far from tonight's event: http://www.geonet.org.nz/news/article-dec-13-2007-update-on-matata.html -- cheers all Mark Robinson ------------- 21 Dec 1953 Former Iranian leader Mohammed Mosadegh sentenced to three years in jail. 21 Dec 1970 Elvis Presley is designated an honorary anti drug campaigner by President Nixon. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 20 Dec 2007 14:59:48 +0000 Hi Thanks for the links. I did record the earthquake here in Iceland. I got good signal, to my surprice. I hope that everything is ok in NZ because of this earthquake and that damage is not too exstencive. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: Dave Nelson davenn@............... Date: Fri, 21 Dec 2007 06:07:40 +1100 Hi Jon, As I stated in an earlier email the overseas location was a bit out this seems to be a common problem when reporting NZ events I ALWAYS rely on the NZ agency for the correct data It makes me wonder if locations for other overseas events are also similarily mislocated ?? Dave N At 11:23 PM 20/12/2007, you wrote: >Hi >According to EMSC the earthquake was on the island. Not far in, but >inland anyway. >More info can be seen here. >http://www.emsc-csem.org/index.php?page=current&sub=detail&id=72867 > >Regards. -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.17.5/1190 - Release Date: 19/12/2007 7:37 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 20 Dec 2007 19:21:52 +0000 Hi You can see here how the data is from all the providers that EMSC works from. http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Dmsg&view=3D4 This the raw data. I don't think any earthquake net in NZ reports to EMSC or USGS. So they are working on teleseismic data only. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: Dave Nelson davenn@............... Date: Fri, 21 Dec 2007 06:33:25 +1100 At 06:21 AM 21/12/2007, you wrote: >I don't think any earthquake net in NZ reports to EMSC or USGS. So they >are working on teleseismic data only. >Regards. >J=F3n Fr=EDmann and therein lies the problem :) I have noticed over the last 15 yrs= =20 or so that the locations are almost always out but its interesting to note thant even when the info gets to the USGS from NZ its rarely used to correct their loc details :( I also often wonder if this is the reason many guys in our PSN cant get= their P and S picks to match when using the initial data from the USGS/NEIC Watching TV, there seems to be quite a bit of damage in Gisborne from this quake, the area being listed as a natural disaster zone. 11 people=20 hospitalised with various minor injuries. cheers Dave -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.17.5/1190 - Release Date: 19/12/2007 = 7:37 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 20 Dec 2007 19:53:00 +0000 Hi Most of us are in the shadow zone of the planet, relative to location of NZ. So we don't get the P wave directly, just a reflection from somewhere inside the earth. You can clearly see that in the data from my station (hvt). I am even surpriced that I even did record this earthquake. The P wave most have reflected off something under NZ. I haven't found any tv station online at the moment, as I haven't checked. But it is good news that nobody appears to have died in this earthquake. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: NZ quake rolls in From: Mark Robinson mark.robinson@............... Date: Fri, 21 Dec 2007 22:52:50 +1300 Jón Frímann wrote: > Hi > > Thanks for the links. I did record the earthquake here in Iceland. I got > good signal, to my surprice. > > I hope that everything is ok in NZ because of this earthquake and that > damage is not too exstencive. The damage appears to be reasonably extensive but is still being assessed. One elderly woman is reported to have died of a heart attack in the immediate aftermath of the quake. Eleven people were taken by ambulance to hospital with injuries, the most serious of which was a broken leg. It seems we were pretty lucky. http://nz.youtube.com/watch?v=dCv_p4u0oLE -- Mark Robinson ------------- 21 Dec 1953 Former Iranian leader Mohammed Mosadegh sentenced to three years in jail. 21 Dec 1970 Elvis Presley is designated an honorary anti drug campaigner by President Nixon. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: 3.1 in San Jose From: Pete Rowe ptrowe@......... Date: Fri, 21 Dec 2007 07:26:57 -0800 (PST) The 3.1 at 12:14 utc was about 9 miles from me. It woke me up with a thud. My seismometer is now up on my website: www.rowelabs DOT com. Pete ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: 3.1 in San Jose From: "Geoff" gmvoeth@........... Date: Fri, 21 Dec 2007 10:27:17 -0700 Once Aboard Ship i felt an EQ that at first I belived to be a collision of some kind, I waited for an alarm that never came. It was not till I heard on the radio that we just had an EQ I think in Long Beach Ca. Back in the 1970s. I bet they feel EQs in the middle of the ocean even aboard Submarines. These EQs can and do feel like a single thump. Regards geoff ----- Original Message ----- From: "Pete Rowe" To: Sent: Friday, December 21, 2007 8:26 AM Subject: 3.1 in San Jose > The 3.1 at 12:14 utc was about 9 miles from me. It > woke me up with a thud. > My seismometer is now up on my website: www.rowelabs > DOT com. > Pete > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: 3.1 in San Jose << P in the oecan From: "Jim ODonnell" geophysics@.......... Date: Fri, 21 Dec 2007 18:12:25 GMT Hi Geoff- Interesting as water does not support shear waves, only P- so that accou= nts for the 1 thump. There is a low velocity layer (LVL) in the ocean called the SOFAR layer = which traps P waves so they are channeled for long distances. Nice plac= e for a sub to hide I would imagine. The LVL causes the waves to be re= fracted down then back up so they are trapped. See- http://www.whoi.edu/oceanus/viewArticle.do?id=3D2492 Jim Jim O'Donnell = Geological/Geophysical Consultant GEOTECHNICAL APPLICATIONS 702.293.5664 geophysics@.......... 702.281.9081 cell jimo17@........ -- "Geoff" wrote: Once Aboard Ship i felt an EQ that at first I belived to be a collision of some kind, I waited for an alarm that never came. It was not till I heard on the radio that we just had an EQ I think in Long Beach Ca. Back in the 1970s. I bet they feel EQs in the middle of the ocean even aboard Submarines. These EQs can and do feel like a single thump. Regards geoff ----- Original Message ----- = From: "Pete Rowe" To: Sent: Friday, December 21, 2007 8:26 AM Subject: 3.1 in San Jose > The 3.1 at 12:14 utc was about 9 miles from me. It > woke me up with a thud. > My seismometer is now up on my website: www.rowelabs > DOT com. > Pete > = > = > _________________________________________________________________= ___________________ > Never miss a thing. Make Yahoo your home page. = > http://www.yahoo.com/r/hs > __________________________________________________________ > = > Public Seismic Network Mailing List (PSN-L) > = > To leave this list email PSN-L-REQUEST@.............. with = > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) See http://www.seismicnet.com/maillist.html for more information.

Hi Geoff-
Interesting as water does not support shear waves,= only P- so that accounts for the 1 thump.
There is a low velocity la= yer (LVL) in the ocean called the SOFAR layer which traps P waves s= o they are channeled for long distances.  Nice place for a sub to h= ide I would imagine.  The LVL  causes the waves to be refracte= d down then back up so they are trapped.

See-  http://www.whoi.edu/oceanus/viewArticle.do?id=3D2492
Jim
           &= nbsp;      Jim O'Donnell    = ; 
        Geological/Ge= ophysical Consultant
        =    GEOTECHNICAL APPLICATIONS
702.293.5664   =  geophysics@..........
702.281.9081 cell   jimo17@juno= ..com

-- "Geoff" <gmvoeth@...........> wrote:
Once Aboard= Ship i felt an EQ
that at first I belived to be a collision
of so= me kind, I waited for an alarm that
never came. It was not till I hea= rd on the radio
that we just had an EQ I think in Long Beach Ca.
B= ack in the 1970s.

I bet they feel EQs in the middle of the ocean<= BR>even aboard Submarines.

These EQs can and do feel like a singl= e thump.

Regards
geoff

----- Original Message ----- From: "Pete Rowe" <ptrowe@.........>
To: <psn-l@............ com>
Sent: Friday, December 21, 2007 8:26 AM
Subject: 3.1 in Sa= n Jose


> The 3.1 at 12:14 utc was about 9 miles from me. I= t
> woke me up with a thud.
> My seismometer is now up on my= website: www.rowelabs
> DOT com.
> Pete
>
> >      ___________________________________= _________________________________________________
> Never miss a t= hing.  Make Yahoo your home page.
> http://www.yahoo.com/r/h= s
> __________________________________________________________
= >
> Public Seismic Network Mailing List (PSN-L)
>
&g= t; To leave this list email PSN-L-REQUEST@.............. with
> t= he body of the message (first line only): unsubscribe
> See http:/= /www.seismicnet.com/maillist.html for more information.
_____________= _____________________________________________

Public Seismic Netw= ork Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@S= EISMICNET.COM with
the body of the message (first line only): unsubs= cribe
See http://www.seismicnet.com/maillist.html for more informatio= n.

Subject: Andreanof Island From: "Thomas Dick" dickthomas01@............. Date: Fri, 21 Dec 2007 17:38:05 -0600 Did anyone else notice a sharp spike about half the amplitude exactly one minute before the arrival of "P" for the 7:24:36 UTC quake? It is on the vertical USI helicorder? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: 3.1 in San Jose << P in the oecan From: "Geoff" gmvoeth@........... Date: Sat, 22 Dec 2007 11:10:48 -0700 Thank You Jim; I got a song by Eddie Arnold called " JIM " " I wore A tie Today" "Do You Know The Way To San Jose" La La Laallalaa Ward All in fun you know. Yes I think Physics of Oscillatory mechanisims to be interesting. I wish I had known this younger in life and had a more academic family that would have at least given me moral support in my search for the truths. My dad was Blue Collar type that hated Academics. ( ME ) :-) I have seen and heard sounds of diesal engines that were supposedly verified as to have come from 2000 miles away of snorklning subs and I bet that is the the layer the sound was channeled through. The speed of sound is simply the point at which compressional forces are significant like a bunch of little springs pushing back at you then past that point the coefficiend of drag reduces to maybe 0.5 of what it was at the speed of sound which was about 4X the coefficient below the transonic range of Mach 0.85 to Mach 1.15 or so. If we could understand fully the compressional forces that create the sound barrier we might have a better insight to the light speed barrier because even though scientists belive no Ether Exist through which light travels if it is in fact a wave similar things that wew can not sense might be at work. The skin of aircraft would wrinkle due to the fact all the aircraft did not all pass the sound barrier at the very same time these little compressional springs can do terrible damage. I have this suspicion that the speed of sound is also a limitation of tornadic winds when you measure the speed of one wall against the ither. It all has to do with compressional forces. You might see these heat signatures in photos taken by a high resolution infrared camera. A tornado is a focus of energy that is created and maintained by the laws of physics. It seems to be periodic due to its rotational nature and possibly may be sensed through the ground or air vibrations it produces. I do not what kind of sensor would be needed our geophones do not seem good enough. I understand there used to be some kind of CW sonar placed in this area in what is called the Sea of Japan and No one knew who placed the transmitter there but it had to be one of the more technological Countries. Vibration or oscillatory mechanisims are all affected by similar ideas and I guess what we learn about these things can be applied elsewhere in every discipline because they are laws ( theorys ) of Nature which are universal. Siociology, Psychology, Stock Market ??? You might apply what we learn in seismology just about anywhere periodic things happen. Regards, geoff ----- Original Message ----- From: "Jim ODonnell" To: Sent: Friday, December 21, 2007 11:12 AM Subject: Re: 3.1 in San Jose << P in the oecan Hi Geoff- Interesting as water does not support shear waves, only P- so that accounts for the 1 thump. There is a low velocity layer (LVL) in the ocean called the SOFAR layer which traps P waves so they are channeled for long distances. Nice place for a sub to hide I would imagine. The LVL causes the waves to be refracted down then back up so they are trapped. See- http://www.whoi.edu/oceanus/viewArticle.do?id=2492 Jim Jim O'Donnell Geological/Geophysical Consultant GEOTECHNICAL APPLICATIONS 702.293.5664 geophysics@.......... 702.281.9081 cell jimo17@........ -- "Geoff" wrote: Once Aboard Ship i felt an EQ that at first I belived to be a collision of some kind, I waited for an alarm that never came. It was not till I heard on the radio that we just had an EQ I think in Long Beach Ca. Back in the 1970s. I bet they feel EQs in the middle of the ocean even aboard Submarines. These EQs can and do feel like a single thump. Regards geoff ----- Original Message ----- From: "Pete Rowe" To: Sent: Friday, December 21, 2007 8:26 AM Subject: 3.1 in San Jose > The 3.1 at 12:14 utc was about 9 miles from me. It > woke me up with a thud. > My seismometer is now up on my website: www.rowelabs > DOT com. > Pete > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 09:05:00 -0600 Hello To All, I have been trying to compile a list of stations posting frequently on the PSN Net: who they are and where they are. So far, I lack the following names. (I have the locations from their postings.) Fraijanes, Guatemala Locust Valley, NY Knoa, HI Ellensburg,WA Aptos, CA Sea Ranch, CA If you would please email me your name, I could finish the compilation. Thank you very much. (Additional information regarding each seismograph at your station would be interesting too.) Seasons Greeting to ALL, Jerry Payton gpayton880@.......
Hello To All,
 
I have been trying to compile a list of stations posting = frequently on=20 the PSN Net: who they are and where they are.
 
So far, I lack the following names.  (I have the locations = from their=20 postings.)
 
    Fraijanes, Guatemala
    Locust Valley, NY
    Knoa, HI
    Ellensburg,WA
    Aptos, CA
    Sea Ranch, CA
 
If you would please email me your name, I could finish the=20 compilation.  Thank you very much.  (Additional information = regarding=20 each seismograph at your station would be interesting too.)
 
Seasons Greeting to ALL,
Jerry Payton
 
 
Subject: Re: Map From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 10:20:35 -0600 Yes, & No. I had seen it in my ancient past, but did not remember where. I also questioned it being up-to-date. I see that page one is dated 2005, but page two is 2007. It WILL be a help,. thanks. Jerry ----- Original Message ----- From: tchannel1@............ To: Jerry Payton Sent: Sunday, December 23, 2007 10:12 AM Subject: Map Hi Jerry, Do you know of this map? http://www.sydneystormcity.com/map.htm It may have the info you are looking for. Ted
Yes, & No.  I had seen it in my ancient past, but did = not=20 remember where.  I also questioned it being up-to-date.  = I see=20 that page one is dated 2005, but page two is 2007. 
 
It WILL be a help,. thanks.
 
Jerry
 
----- Original Message -----=20
From: tchannel1@............
Sent: Sunday, December 23, 2007 10:12 AM
Subject: Map

Hi Jerry,  Do you know of this = map?  http://www.sydneystormcit= y.com/map.htm  =20 It may have the info you are looking for.
Ted
Subject: How to arrange the magnets? From: tchannel1@............ Date: Sun, 23 Dec 2007 09:34:25 -0700 Hi Folks, I want to make a simple Pendulum with magnets on the end, = which swings like a plumb bob over a ring shaped coil (dough nut = shaped). I think if the magnet was the same shape and size as the coil, it would = neutralize the voltage as it moved. As it would be North side down and = South side up, so of the same North pole would stimulate two parts of = the coil at the same time. In this case it should be One North and one = South. I think if I used two square magnets, one N pole down and one S pole = down, that would work for swinging, say East and West, but would not = create much if it swung North and South. Perhaps I could use four magnets, N, S, N, S? I could make the coil square or round. =20 In this experiment, I need all the magnets to float above the coil. = How might I arrange the magnets? Thanks, Ted
Hi Folks,   I want to make a = simple=20 Pendulum with  magnets on the end, which swings like a plumb bob = over a=20 ring shaped coil  (dough nut shaped).
 
I think if the magnet was the same = shape and size=20 as the coil, it would neutralize the voltage as it moved.  As it = would be=20 North side down and South side up, so of the same North pole would = stimulate two=20 parts of the coil at the same time. In this case it should=20 be One North and one South.
 
I think if I used two square magnets, = one N pole=20 down and one S pole down, that would work for swinging, say East and = West, but=20 would not create much if it swung North and South.
Perhaps I could use four magnets, N, S, = N,=20 S?
 
I could make the coil square or = round.  =20
 
In this experiment, I need all the = magnets to float=20 above the coil.   How might I arrange the = magnets?
 
Thanks, Ted
 
 
Subject: Masked Man Questions From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 11:42:14 -0600 Thanks to Ted and Chris, I have filled in the missing names. THANK YOU, Jerry
Thanks to Ted and Chris, I have filled in the missing names.  = THANK=20 YOU,
 
Jerry
Subject: Re: How to arrange the magnets? From: ChrisAtUpw@....... Date: Sun, 23 Dec 2007 14:33:14 EST In a message dated 2007/12/23, tchannel1@............ writes: > I could make the coil square or round. In this experiment, I need all the > magnets to float above the coil. How might I arrange the magnets? Hi Ted, Think coils, not magnets! Use four coils, one pair N/S and the other E/W, connected in opposition on a cross, with the magnet pole in the centre. Then when the magnet swings N & S, or E/W, you will get the resolved components of that signal. Regards, Chris Chapman In a me= ssage dated 2007/12/23, tchannel1@............ writes:

I could make the coil square or= round. In this experiment, I need all the magnets to float above the coil.=20= How might I arrange the magnets?


Hi Ted,

       Think coils, not magnets!

       Use four coils, one pair N/S and the ot= her E/W, connected in opposition on a cross, with the magnet pole in the cen= tre. Then when the magnet swings N & S, or E/W, you will get  the r= esolved components of that signal.

       Regards,

       Chris Chapman  Subject: Re: Who Is That Masked Man?? From: Dave Nelson davenn@............... Date: Mon, 24 Dec 2007 08:34:19 +1100 Jerry we already have a PSN database see www.sydneystormcity.com/map.htm on which you will find all the locations and info of the many stations that have so far sent me their data, well over 100 stations to date :) cheers Dave Nelson Sydney At 02:05 AM 24/12/2007, you wrote: >Hello To All, >I have been trying to compile a list of stations posting frequently on the >PSN Net: who they are and where they are. >So far, I lack the following names. (I have the locations from their >postings.) > Fraijanes, Guatemala > Locust Valley, NY > Knoa, HI > Ellensburg,WA > Aptos, CA > Sea Ranch, CA > >If you would please email me your name, I could finish the >compilation. Thank you very much. (Additional information regarding each >seismograph at your station would be interesting too.) > >Seasons Greeting to ALL, >Jerry Payton >gpayton880@....... -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.17.6/1193 - Release Date: 22/12/2007 2:02 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 15:40:52 -0600 Yes, thank you Dave. Are all the NZ stations listed still operating? The document is a little dated. Jerry ----- Original Message ----- From: Dave Nelson To: psn-l@.............. Sent: Sunday, December 23, 2007 3:34 PM Subject: Re: Who Is That Masked Man?? Jerry we already have a PSN database see www.sydneystormcity.com/map.htm on which you will find all the locations and info of the many stations that have so far sent me their data, well over 100 stations to date :) cheers Dave Nelson Sydney At 02:05 AM 24/12/2007, you wrote: >Hello To All, >I have been trying to compile a list of stations posting frequently on the >PSN Net: who they are and where they are. >So far, I lack the following names. (I have the locations from their >postings.) > Fraijanes, Guatemala > Locust Valley, NY > Knoa, HI > Ellensburg,WA > Aptos, CA > Sea Ranch, CA > >If you would please email me your name, I could finish the >compilation. Thank you very much. (Additional information regarding each >seismograph at your station would be interesting too.) > >Seasons Greeting to ALL, >Jerry Payton >gpayton880@....... -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.17.6/1193 - Release Date: 22/12/2007 2:02 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Yes, thank you Dave.  Are all the NZ stations listed still=20 operating?  The document is a little dated.
Jerry
 
 
----- Original Message -----=20
From: Dave=20 Nelson
Sent: Sunday, December 23, 2007 3:34 PM
Subject: Re: Who Is That Masked Man??

Jerry
we already have a PSN database

 =20 see   www.sydneystormcity.com/m= ap.htm

on=20 which you will find all the locations and info of the many stations that =
have
so far sent me their data,  well over 100 stations to=20 date  :)

cheers
Dave Nelson
Sydney


At 02:05 = AM=20 24/12/2007, you wrote:
>Hello To All,
>I have been trying to = compile=20 a list of stations posting frequently on the
>PSN Net: who they = are and=20 where they are.
>So far, I lack the following names.  (I have = the=20 locations from their
>postings.)
>    = Fraijanes,=20 Guatemala
>     Locust Valley,=20 NY
>     Knoa, = HI
>    =20 Ellensburg,WA
>     Aptos,=20 CA
>     Sea Ranch, CA
>
>If you = would=20 please email me your name, I could finish the
>compilation.  = Thank=20 you very much.  (Additional information regarding each =
>seismograph=20 at your station would be interesting too.)
>
>Seasons = Greeting to=20 ALL,
>Jerry Payton
><gpayton880@.......">mailto:gpayton880@c= ox.net>gpayton880@.......


--=20
No virus found in this outgoing message.
Checked by AVG Free = Edition.=20
Version: 7.5.516 / Virus Database: 269.17.6/1193 - Release Date: = 22/12/2007=20 2:02=20 PM


__________________________________________________________<= BR>
Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Who Is That Masked Man?? From: Dave Nelson davenn@............... Date: Mon, 24 Dec 2007 08:49:41 +1100 all but my station as I have moved to australia just left it there for memory sake ;) I can only update data as people send me updates for their station otherwise I have to assume it is still operating as when data was sent to me periodically ... usually once a year I put a call out of the PSN list for people to update their info some times I get responses some times I dont cest la vi :) in fact as a result of your posting today I have had 2 more stations email me their data, they will be added to page 2 of the database over the next few days cheers Dave At 08:40 AM 24/12/2007, you wrote: >Yes, thank you Dave. Are all the NZ stations listed still operating? The >document is a little dated. >Jerry -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.17.6/1193 - Release Date: 22/12/2007 2:02 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 15:58:10 -0600 Good Dave. Glad that I stirred the up for the list and glad to know that you are the care taker of the list too. I kinda had that "hope" in the back of my mind besides clarifying who was who (or is that whom?). :>) I've noticed that there are several regular posters that are not on the list and that a large number that are do not post anything. Like you say, "cest la vi." OK, I'll note that you are in AU now. Best wishes, Jerry ----- Original Message ----- From: Dave Nelson To: psn-l@.............. Sent: Sunday, December 23, 2007 3:49 PM Subject: Re: Who Is That Masked Man?? all but my station as I have moved to australia just left it there for memory sake ;) I can only update data as people send me updates for their station otherwise I have to assume it is still operating as when data was sent to me periodically ... usually once a year I put a call out of the PSN list for people to update their info some times I get responses some times I dont cest la vi :) in fact as a result of your posting today I have had 2 more stations email me their data, they will be added to page 2 of the database over the next few days cheers Dave At 08:40 AM 24/12/2007, you wrote: >Yes, thank you Dave. Are all the NZ stations listed still operating? The >document is a little dated. >Jerry -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.17.6/1193 - Release Date: 22/12/2007 2:02 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Good Dave.  Glad that I stirred the up for the list and glad = to know=20 that you are the care taker of the list too.  I kinda had that = "hope" in=20 the back of my mind besides clarifying who was who (or is that whom?).=20 :>)
 
I've noticed that there are several regular posters that are not on = the=20 list and that a large number that are do not post anything.  Like = you say,=20 "cest la vi."
 
OK, I'll note that you are in AU now.
 
Best wishes,
Jerry
 
 
----- Original Message -----=20
From: Dave=20 Nelson
Sent: Sunday, December 23, 2007 3:49 PM
Subject: Re: Who Is That Masked Man??



all but my station   as I have moved to = australia

just left it there for memory sake   = ;)

I can=20 only update data as people send me updates for their = station
otherwise I have=20 to assume it is  still operating as when data was
sent to=20 me

periodically ... usually  once a year I put a call out of = the PSN=20 list for
people to
update their info
some times I get = responses some=20 times I dont     cest la vi    =20 :)

in fact as a result of your posting today   I have = had 2=20 more stations
email me
their data,   they will be added = to page=20 2 of the database over the next
few = days

cheers
Dave


At=20 08:40 AM 24/12/2007, you wrote:

>Yes, thank you Dave.  = Are all=20 the NZ stations listed still operating?  The
>document is a = little=20 dated.
>Jerry


--
No virus found in this outgoing=20 message.
Checked by AVG Free Edition.
Version: 7.5.516 / Virus = Database:=20 269.17.6/1193 - Release Date: 22/12/2007 2:02=20 PM


__________________________________________________________<= BR>
Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
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Subject: Re: Who Is That Masked Man?? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 23 Dec 2007 22:03:15 +0000 Hi I am soon to have multi stations running over few places in Iceland. I am going to start a station near Hekla Volcano in 2008, hopefully around June or July. Then I am going to add a third station also in 2008. So in 2008 I hope to start two new stations. In 2009 I am going to add one station, at least. But I hope to add two more stations in 2009. But all of this is money depened and what I can manage. There are also going to be at least one station that is going to mesure earthquakes that I am going to get connection two, even if they are not run or owned by me. I did send update last time when I did add a station, but it didn't get in there. At least I think so. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 16:05:40 -0600 Thanks Jon, You ARE listed and I am keeping up with your expansions, as best we can. Regards, Jerry
Thanks Jon, You ARE listed and I am keeping up with = your=20 expansions, as best we can.
Regards,
Jerry
 
Subject: Re: How to arrange the magnets? From: "Geoff" gmvoeth@........... Date: Sun, 23 Dec 2007 15:21:53 -0700 You Need to think of making the lines of flux around the magnet visible then arrange things so that the lines of flux cut the wires at 90 deg ( normal ) whenever there is relative motion. Also one side should compliment the other in pushing the current about a closed loop. You can greatly increase the lines of force by using an iron core like a solinoid coil but you most probably will not get any kind linear relationship between velocity and motion or so iut seems to me. I have tried it in the past using a flat speaker magnet hoovering atop the coil as well as a rod magnet in the center of the coil as well as the solinoid idea the solinoid idea was most sensitive but was never sure about free period since there is a magnetic attraction to the core of the solinoid. I never finished this idea since I went to a manufactured geophone because a pendulum seemed just too big and troublesome to bury in the ground. If you can use copper plate and magnet damping seperate from the sensor you can realize the max sensitivity of the pickup coil or so it seems. Regards; geoff ----- Original Message ----- From: To: "psn" Sent: Sunday, December 23, 2007 9:34 AM Subject: How to arrange the magnets? Hi Folks, I want to make a simple Pendulum with magnets on the end, which swings like a plumb bob over a ring shaped coil (dough nut shaped). I think if the magnet was the same shape and size as the coil, it would neutralize the voltage as it moved. As it would be North side down and South side up, so of the same North pole would stimulate two parts of the coil at the same time. In this case it should be One North and one South. I think if I used two square magnets, one N pole down and one S pole down, that would work for swinging, say East and West, but would not create much if it swung North and South. Perhaps I could use four magnets, N, S, N, S? I could make the coil square or round. In this experiment, I need all the magnets to float above the coil. How might I arrange the magnets? Thanks, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Who Is That Masked Man?? From: "Bob Hammond" propgrinder@......... Date: Sun, 23 Dec 2007 13:33:53 -0900 Hi Jerry, Yes, there are a bunch of us PSNers who listen but don't generally post. Guess it's the old timers mostly. Anyhow, Dave has always done a great job in keeping the list updated. I'd think it would be a duplication of his efforts for you to do another of the same. regards to all, Bob Hammond PSN-Alaska http://wulik.com On Dec 23, 2007 1:05 PM, Jerry Payton wrote: > Thanks Jon, You *ARE* listed and I am keeping up with your expansions, as > best we can. > Regards, > Jerry > > Hi Jerry,

Yes, there are a bunch of us PSNers who listen but don't generally post.  Guess it's the old timers mostly.  Anyhow, Dave has always done a great job in keeping the list updated.  I'd think it would be a duplication of his efforts for you to do another of the same.

regards to all,

Bob Hammond
PSN-Alaska
http://wulik.com


On Dec 23, 2007 1:05 PM, Jerry Payton < gpayton880@.......> wrote:
Thanks Jon, You ARE listed and I am keeping up with your expansions, as best we can.
Regards,
Jerry
 

Subject: Re: Who Is That Masked Man?? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 23 Dec 2007 22:48:20 +0000 Hi all For those intrested. I am always intrested in getting more helcorders on my web page. Just send me a email and I will add it when I update my earthquake web pages. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 16:48:39 -0600 Yes, you are right Bob. I did NOT have that in mind. I only was trying to identify WHO was WHERE, not a new list. ----- Original Message ----- From: Bob Hammond To: psn-l@.............. Sent: Sunday, December 23, 2007 4:33 PM Subject: Re: Who Is That Masked Man?? Hi Jerry, Yes, there are a bunch of us PSNers who listen but don't generally post. Guess it's the old timers mostly. Anyhow, Dave has always done a great job in keeping the list updated. I'd think it would be a duplication of his efforts for you to do another of the same. regards to all, Bob Hammond PSN-Alaska http://wulik.com On Dec 23, 2007 1:05 PM, Jerry Payton < gpayton880@.......> wrote: Thanks Jon, You ARE listed and I am keeping up with your expansions, as best we can. Regards, Jerry
Yes, you are right Bob.  I did NOT have that in mind.  I = only was=20 trying to identify WHO was WHERE, not a new list.
 
 
----- Original Message -----=20
From: Bob = Hammond=20
Sent: Sunday, December 23, 2007 4:33 PM
Subject: Re: Who Is That Masked Man??

Hi Jerry,

Yes, there are a bunch of us PSNers who = listen=20 but don't generally post.  Guess it's the old timers mostly.  = Anyhow,=20 Dave has always done a great job in keeping the list updated.  I'd = think it=20 would be a duplication of his efforts for you to do another of the same. =

regards to all,

Bob Hammond
PSN-Alaska
http://wulik.com


On Dec 23, 2007 1:05 PM, Jerry Payton < gpayton880@.......> = wrote:
Thanks Jon, You ARE listed and I am keeping up with = your=20 expansions, as best we can.
Regards,
Jerry
 

Subject: Re: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Sun, 23 Dec 2007 20:00:06 -0600 "Yes, there are a bunch of us PSNers who listen but don't generally post. Guess it's the old timers mostly. regards to all, Bob Hammond PSN-Alaska" Perhaps you are right Bob, but what is the purpose of posting to the PSN net if each individual does not post their capture for comparison? We newbies need the old-timers and experts to show us how it's done.......not just verbally. (Just my thoughts on the matter. Perhaps I am out of line, sorry." Best Wishes to ALL, Jerry
"Yes, there are a bunch of us PSNers who listen but don't generally = post.  Guess it's the old timers mostly.
regards to all,  Bob Hammond PSN-Alaska"
 
Perhaps you are right Bob, but what is the purpose of posting = to the=20 PSN net if each individual does not post their capture for=20 comparison?  We newbies need the old-timers and experts to = show us=20 how it's done.......not just verbally.  (Just my thoughts on = the=20 matter.  Perhaps I am out of line, sorry."
 
Best Wishes to ALL,
Jerry
Subject: Re: Who Is That Masked Man?? From: Pete Rowe ptrowe@......... Date: Mon, 24 Dec 2007 09:50:37 -0800 (PST) Good idea, Jerry I'm an old timer (my seismometer has been running since 1988) but I've forgotten how to post files and have been too lazy to find out. A refresher would be nice. Happy holidays Pete --- Jerry Payton wrote: > "Yes, there are a bunch of us PSNers who listen but > don't generally post. > Guess it's the old timers mostly. > regards to all, Bob Hammond PSN-Alaska" > > Perhaps you are right Bob, but what is the purpose > of posting to the PSN net > if each individual does not post their capture for > comparison? We newbies > need the old-timers and experts to show us how it's > done.......not just > verbally. (Just my thoughts on the matter. Perhaps > I am out of line, > sorry." > > Best Wishes to ALL, > Jerry > ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Who Is That Masked Man?? From: "Jerry Payton" gpayton880@....... Date: Mon, 24 Dec 2007 12:03:25 -0600 Happy Holidays to you too. I thoroughly understand "burn out", but learning from you "Old Timers" (smile) is always useful........IF it sticks. Jerry ----- Original Message ----- From: Pete Rowe To: psn-l@.............. Sent: Monday, December 24, 2007 11:50 AM Subject: Re: Who Is That Masked Man?? Good idea, Jerry I'm an old timer (my seismometer has been running since 1988) but I've forgotten how to post files and have been too lazy to find out. A refresher would be nice. Happy holidays Pete --- Jerry Payton wrote: > "Yes, there are a bunch of us PSNers who listen but > don't generally post. > Guess it's the old timers mostly. > regards to all, Bob Hammond PSN-Alaska" > > Perhaps you are right Bob, but what is the purpose > of posting to the PSN net > if each individual does not post their capture for > comparison? We newbies > need the old-timers and experts to show us how it's > done.......not just > verbally. (Just my thoughts on the matter. Perhaps > I am out of line, > sorry." > > Best Wishes to ALL, > Jerry > ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Happy Holidays to you too.  I thoroughly understand "burn = out", but=20 learning from you "Old Timers" (smile) is always useful........IF it=20 sticks.
Jerry
 
 
----- Original Message -----=20
From: Pete Rowe =
Sent: Monday, December 24, 2007 11:50 AM
Subject: Re: Who Is That Masked Man??

Good idea, Jerry
I'm an old timer (my seismometer has = been=20 running
since 1988) but I've forgotten how to post files and
have = been too=20 lazy to find out. A refresher would be
nice.
Happy = holidays
Pete
---=20 Jerry Payton <gpayton880@.......>=20 wrote:

> "Yes, there are a bunch of us PSNers who listen = but
>=20 don't generally post.
> Guess it's the old timers mostly.
> = regards=20 to all,  Bob Hammond PSN-Alaska"
>
> Perhaps you are = right=20 Bob, but what is the purpose
> of posting to the PSN net
> = if each=20 individual does not post their capture for
> comparison?  We = newbies=20
> need the old-timers and experts to show us how it's
>=20 done.......not just
> verbally.  (Just my thoughts on the=20 matter.  Perhaps
> I am out of line,
> sorry."
> =
> Best Wishes to ALL,
> Jerry
>=20



     =20 _________________________________________________________________________= ___________
Never=20 miss a thing.  Make Yahoo your home page.
http://www.yahoo.com/r/hs
_____= _____________________________________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Who Is That Masked Man?? From: "Bob Hammond" propgrinder@......... Date: Wed, 26 Dec 2007 13:29:46 -0900 6.2 in the Fox Islands, Aleutians, now rolling in. Bob Hammond PSN-Alaska On Dec 24, 2007 9:03 AM, Jerry Payton wrote: > Happy Holidays to you too. I thoroughly understand "burn out", but > learning from you "Old Timers" (smile) is always useful........IF it sticks. > Jerry > > > ----- Original Message ----- *From:* Pete Rowe > *To:* psn-l@.............. > *Sent:* Monday, December 24, 2007 11:50 AM > *Subject:* Re: Who Is That Masked Man?? > > Good idea, Jerry > I'm an old timer (my seismometer has been running > since 1988) but I've forgotten how to post files and > have been too lazy to find out. A refresher would be > nice. > Happy holidays > Pete > --- Jerry Payton wrote: > > > "Yes, there are a bunch of us PSNers who listen but > > don't generally post. > > Guess it's the old timers mostly. > > regards to all, Bob Hammond PSN-Alaska" > > > > Perhaps you are right Bob, but what is the purpose > > of posting to the PSN net > > if each individual does not post their capture for > > comparison? We newbies > > need the old-timers and experts to show us how it's > > done.......not just > > verbally. (Just my thoughts on the matter. Perhaps > > I am out of line, > > sorry." > > > > Best Wishes to ALL, > > Jerry > > > > > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >
6.2 in the Fox Islands, Aleutians, now rolling in.
 
Bob Hammond
PSN-Alaska

On Dec 24, 2007 9:03 AM, Jerry Payton <gpayton880@.......> wrote:
Happy Holidays to you too.  I thoroughly understand "burn out", but learning from you "Old Timers" (smile) is always useful........IF it sticks.
Jerry
 
 
----- Original Message -----
From: Pete Rowe
Sent: Monday, December 24, 2007 11:50 AM
Subject: Re: Who Is That Masked Man??

Good idea, Jerry
I'm an old timer (my seismometer has been running
since 1988) but I've forgotten how to post files and
have been too lazy to find out. A refresher would be
nice.
Happy holidays
Pete
--- Jerry Payton <gpayton880@.......> wrote:

> "Yes, there are a bunch of us PSNers who listen but
> don't generally post.
> Guess it's the old timers mostly.
> regards to all,  Bob Hammond PSN-Alaska"
>
> Perhaps you are right Bob, but what is the purpose
> of posting to the PSN net
> if each individual does not post their capture for
> comparison?  We newbies
> need the old-timers and experts to show us how it's
> done.......not just
> verbally.  (Just my thoughts on the matter.  Perhaps
> I am out of line,
> sorry."
>
> Best Wishes to ALL,
> Jerry
>



      ____________________________________________________________________________________
Never miss a thing.  Make Yahoo your home page.
http://www.yahoo.com/r/hs
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.

Subject: 6.5, Fox Islands, Aleutian Islands, Alaska From: "Bob Hammond" propgrinder@......... Date: Wed, 26 Dec 2007 13:30:49 -0900 whoops, it's a 6.5 On Dec 26, 2007 1:29 PM, Bob Hammond wrote: > 6.2 in the Fox Islands, Aleutians, now rolling in. > > Bob Hammond > PSN-Alaska > > On Dec 24, 2007 9:03 AM, Jerry Payton wrote: > > > Happy Holidays to you too. I thoroughly understand "burn out", but > > learning from you "Old Timers" (smile) is always useful........IF it sticks. > > Jerry > > > > > > ----- Original Message ----- *From:* Pete Rowe > > *To:* psn-l@.............. > > *Sent:* Monday, December 24, 2007 11:50 AM > > *Subject:* Re: Who Is That Masked Man?? > > > > Good idea, Jerry > > I'm an old timer (my seismometer has been running > > since 1988) but I've forgotten how to post files and > > have been too lazy to find out. A refresher would be > > nice. > > Happy holidays > > Pete > > --- Jerry Payton wrote: > > > > > "Yes, there are a bunch of us PSNers who listen but > > > don't generally post. > > > Guess it's the old timers mostly. > > > regards to all, Bob Hammond PSN-Alaska" > > > > > > Perhaps you are right Bob, but what is the purpose > > > of posting to the PSN net > > > if each individual does not post their capture for > > > comparison? We newbies > > > need the old-timers and experts to show us how it's > > > done.......not just > > > verbally. (Just my thoughts on the matter. Perhaps > > > I am out of line, > > > sorry." > > > > > > Best Wishes to ALL, > > > Jerry > > > > > > > > > > > > > ____________________________________________________________________________________ > > Never miss a thing. Make Yahoo your home page. > > http://www.yahoo.com/r/hs > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > > >
whoops, it's a 6.5


 
On Dec 26, 2007 1:29 PM, Bob Hammond <propgrinder@.........> wrote:
6.2 in the Fox Islands, Aleutians, now rolling in.
 
Bob Hammond
PSN-Alaska
On Dec 24, 2007 9:03 AM, Jerry Payton <gpayton880@.......> wrote:
Happy Holidays to you too.  I thoroughly understand "burn out", but learning from you "Old Timers" (smile) is always useful........IF it sticks.
Jerry
 
 
----- Original Message -----
From: Pete Rowe
Sent: Monday, December 24, 2007 11:50 AM
Subject: Re: Who Is That Masked Man??

Good idea, Jerry
I'm an old timer (my seismometer has been running
since 1988) but I've forgotten how to post files and
have been too lazy to find out. A refresher would be
nice.
Happy holidays
Pete
--- Jerry Payton <gpayton880@.......> wrote:

> "Yes, there are a bunch of us PSNers who listen but
> don't generally post.
> Guess it's the old timers mostly.
> regards to all,  Bob Hammond PSN-Alaska"
>
> Perhaps you are right Bob, but what is the purpose
> of posting to the PSN net
> if each individual does not post their capture for
> comparison?  We newbies
> need the old-timers and experts to show us how it's
> done.......not just
> verbally.  (Just my thoughts on the matter.  Perhaps
> I am out of line,
> sorry."
>
> Best Wishes to ALL,
> Jerry
>



      ____________________________________________________________________________________
Never miss a thing.  Make Yahoo your home page.
http://www.yahoo.com/r/hs
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.


Subject: Re: 6.5, Fox Islands, Aleutian Islands, Alaska From: "Bob Hammond" propgrinder@......... Date: Wed, 26 Dec 2007 13:31:39 -0900 http://wulik.com/current.htm On Dec 26, 2007 1:30 PM, Bob Hammond wrote: > whoops, it's a 6.5 > > > > On Dec 26, 2007 1:29 PM, Bob Hammond wrote: > > > 6.2 in the Fox Islands, Aleutians, now rolling in. > > > > Bob Hammond > > PSN-Alaska > > > > On Dec 24, 2007 9:03 AM, Jerry Payton wrote: > > > > > Happy Holidays to you too. I thoroughly understand "burn out", but > > > learning from you "Old Timers" (smile) is always useful........IF it sticks. > > > Jerry > > > > > > > > > ----- Original Message ----- *From:* Pete Rowe > > > *To:* psn-l@.............. > > > *Sent:* Monday, December 24, 2007 11:50 AM > > > *Subject:* Re: Who Is That Masked Man?? > > > > > > Good idea, Jerry > > > I'm an old timer (my seismometer has been running > > > since 1988) but I've forgotten how to post files and > > > have been too lazy to find out. A refresher would be > > > nice. > > > Happy holidays > > > Pete > > > --- Jerry Payton wrote: > > > > > > > "Yes, there are a bunch of us PSNers who listen but > > > > don't generally post. > > > > Guess it's the old timers mostly. > > > > regards to all, Bob Hammond PSN-Alaska" > > > > > > > > Perhaps you are right Bob, but what is the purpose > > > > of posting to the PSN net > > > > if each individual does not post their capture for > > > > comparison? We newbies > > > > need the old-timers and experts to show us how it's > > > > done.......not just > > > > verbally. (Just my thoughts on the matter. Perhaps > > > > I am out of line, > > > > sorry." > > > > > > > > Best Wishes to ALL, > > > > Jerry > > > > > > > > > > > > > > > > > > > ____________________________________________________________________________________ > > > Never miss a thing. Make Yahoo your home page. > > > http://www.yahoo.com/r/hs > > > __________________________________________________________ > > > > > > Public Seismic Network Mailing List (PSN-L) > > > > > > To leave this list email PSN-L-REQUEST@.............. with > > > the body of the message (first line only): unsubscribe > > > See http://www.seismicnet.com/maillist.html for more information. > > > > > > > > http://wulik.com/current.htm

On Dec 26, 2007 1:30 PM, Bob Hammond <propgrinder@.........> wrote:
whoops, it's a 6.5


 
On Dec 26, 2007 1:29 PM, Bob Hammond <propgrinder@.........> wrote:
6.2 in the Fox Islands, Aleutians, now rolling in.
 
Bob Hammond
PSN-Alaska
On Dec 24, 2007 9:03 AM, Jerry Payton <gpayton880@.......> wrote:
Happy Holidays to you too.  I thoroughly understand "burn out", but learning from you "Old Timers" (smile) is always useful........IF it sticks.
Jerry
 
 
----- Original Message -----
From: Pete Rowe
Sent: Monday, December 24, 2007 11:50 AM
Subject: Re: Who Is That Masked Man??

Good idea, Jerry
I'm an old timer (my seismometer has been running
since 1988) but I've forgotten how to post files and
have been too lazy to find out. A refresher would be
nice.
Happy holidays
Pete
--- Jerry Payton <gpayton880@.......> wrote:

> "Yes, there are a bunch of us PSNers who listen but
> don't generally post.
> Guess it's the old timers mostly.
> regards to all,  Bob Hammond PSN-Alaska"
>
> Perhaps you are right Bob, but what is the purpose
> of posting to the PSN net
> if each individual does not post their capture for
> comparison?  We newbies
> need the old-timers and experts to show us how it's
> done.......not just
> verbally.  (Just my thoughts on the matter.  Perhaps
> I am out of line,
> sorry."
>
> Best Wishes to ALL,
> Jerry
>



      ____________________________________________________________________________________
Never miss a thing.  Make Yahoo your home page.
http://www.yahoo.com/r/hs
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.



Subject: Risk of large earthquake near Virgin Islands From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 28 Dec 2007 19:35:40 +0000 Hi all I am seeing a pattern that suggests a 50% chance of a mag 6.0> earthquake near Virgin Islands, I am expecting it soon given the patterns of earthquakes that have been appearing in the past 48 hours. Also, happy christmas. :-) Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Subduction Zone Question From: "Jerry Payton" gpayton880@....... Date: Mon, 31 Dec 2007 09:17:50 -0600 Hi All, Happy New Year. I have a question about Subduction Zones and their angle of incidence down to the mantle. If I remember correctly, the Mariana Trench is quite steep while others are not. I was wondering specifically about the Pacific and Juan de Fuca plates and their subduction angle under the Cascade Mountains. Specifically, I am wondering how far the subduction angel goes inland before it melts into the mantle? The 3.8 event at the Yellowstone Park area brought the question to mind. I know there is supposed to be a Hot Pocket under that area and potentially explosive, but I was wondering if the subduction wedge extended inland that far. Truthfully, I don't know how far Yellowstone is from the coast. Of course, the farther inland, the deeper the wedge would be. The Yellowstone event was shallow (6.8 km), and obviously not what I an asking about. Nevertheless, I was wondering about that specific area anyway. Anybody know? What the heck do you have to think about anyway, New Years parties? Regards, Jerry
Hi All,
 
Happy New Year.
 
I have a question about Subduction Zones and their angle of=20 incidence down to the mantle.  If I remember correctly, = the=20 Mariana Trench is quite steep while others are not. 
 
I was wondering specifically about the Pacific and Juan de Fuca = plates and=20 their subduction angle under the Cascade Mountains.  Specifically, = I am=20 wondering how far the subduction angel goes inland before it melts into = the=20 mantle? 
 
The 3.8 event at the Yellowstone Park area brought the question to=20 mind.  I know there is supposed to be a Hot Pocket under that area = and=20 potentially explosive, but I was wondering if the subduction wedge = extended=20 inland that far.  Truthfully, I don't know how far Yellowstone is = from the=20 coast. 
 
Of course, the farther inland, the deeper the wedge would be.  = The=20 Yellowstone event was shallow (6.8 km), and obviously not what I an = asking=20 about.  Nevertheless, I was wondering about that specific area=20 anyway.  Anybody know?
 
What the heck do you have to think about anyway, New Years = parties?
 
Regards,
Jerry